diff --git a/include/xlnt/cell/cell.hpp b/include/xlnt/cell/cell.hpp
index 630753d2..0f678161 100644
--- a/include/xlnt/cell/cell.hpp
+++ b/include/xlnt/cell/cell.hpp
@@ -27,15 +27,20 @@
 #include <string>
 #include <unordered_map>
 
-#include "../styles/style.hpp"
-#include "../common/types.hpp"
+#include <xlnt/common/types.hpp>
 
 namespace xlnt {
     
 enum class calendar;
-    
+
+class alignment;
+class border;
 class cell_reference;
 class comment;
+class fill;
+class font;
+class number_format;
+class protection;
 class relationship;
 class worksheet;
 
@@ -62,6 +67,9 @@ struct cell_impl;
 class cell
 {
 public:
+    /// <summary>
+    /// Enumerates the possible types a cell can be determined by it's current value.
+    /// </summary>
     enum class type
     {
         null,
@@ -72,14 +80,38 @@ public:
         boolean
     };
     
-    static const std::unordered_map<std::string, int> ErrorCodes;
+    /// <summary>
+    /// Return a map of error strings such as #DIV/0! and their associated indices.
+    /// </summary>
+    static const std::unordered_map<std::string, int> error_codes();
     
+    //TODO: Should it be possible to construct and use a cell without a parent worksheet?
+    //(cont'd) If so, it would need to be responsible for allocating and deleting its PIMPL.
+    
+    /// <summary>
+    /// Construct a null cell without a parent.
+    /// Most methods will throw an exception if this cell is not further initialized.
+    /// </summary>
     cell();
-    cell(worksheet worksheet, const cell_reference &reference);
+    
+    /// <summary>
+    /// Construct a cell in worksheet, sheet, at the given reference location (e.g. A1).
+    /// </summary>
+    cell(worksheet sheet, const cell_reference &reference);
+    
+    /// <summary>
+    /// This constructor, provided for convenience, is equivalent to calling:
+    /// cell c(sheet, reference);
+    /// c.set_value(initial_value);
+    /// </summary>
     template<typename T>
-    cell(worksheet worksheet, const cell_reference &reference, const T &initial_value);
+    cell(worksheet sheet, const cell_reference &reference, const T &initial_value);
 
     // value
+    
+    /// <summary>
+    /// Return true if value has been set and has not been cleared using cell::clear_value().
+    /// </summary>
     bool has_value() const;
     
     template<typename T>
@@ -93,10 +125,18 @@ public:
     type get_data_type() const;
     void set_data_type(type t);
     
-    // characteristics
+    // properties
+    
+    /// <summary>
+    /// There's no reason to keep a cell which has no value and is not a placeholder.
+    /// Return true if this cell has no value, style, isn't merged, etc.
+    /// </summary>
     bool garbage_collectible() const;
+    
+    /// <summary>
+    /// Return true iff this cell's number format matches a date format.
+    /// </summary>
     bool is_date() const;
-    std::size_t get_xf_index() const;
     
     // position
     cell_reference get_reference() const;
@@ -176,6 +216,7 @@ public:
     bool operator==(const cell &comparand) const;
     bool operator==(std::nullptr_t) const;
 
+    // friend operators, so we can put cell on either side of comparisons with other types
     friend bool operator==(std::nullptr_t, const cell &cell);
     friend bool operator<(cell left, cell right);
     
@@ -188,6 +229,10 @@ private:
     detail::cell_impl *d_;
 };
 
+/// <summary>
+/// Convenience function for writing cell to an ostream.
+/// Uses cell::to_string() internally.
+/// </summary>
 inline std::ostream &operator<<(std::ostream &stream, const xlnt::cell &cell)
 {
     return stream << cell.to_string();
diff --git a/include/xlnt/reader/comment_reader.hpp b/include/xlnt/reader/comment_reader.hpp
deleted file mode 100644
index 91a0bf1b..00000000
--- a/include/xlnt/reader/comment_reader.hpp
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright (c) 2015 Thomas Fussell
-// Copyright (c) 2010-2015 openpyxl
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE
-//
-// @license: http://www.opensource.org/licenses/mit-license.php
-// @author: see AUTHORS file
-#pragma once
-
-namespace xlnt {
-
-class comment_reader
-{
-
-};
-
-} // namespace xlnt
diff --git a/include/xlnt/reader/style_reader.hpp b/include/xlnt/reader/style_reader.hpp
deleted file mode 100644
index 329c2e03..00000000
--- a/include/xlnt/reader/style_reader.hpp
+++ /dev/null
@@ -1,88 +0,0 @@
-// Copyright (c) 2015 Thomas Fussell
-// Copyright (c) 2010-2015 openpyxl
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE
-//
-// @license: http://www.opensource.org/licenses/mit-license.php
-// @author: see AUTHORS file
-#pragma once
-
-#include <string>
-#include <unordered_map>
-#include <vector>
-
-#include "xlnt/workbook/workbook.hpp"
-
-namespace pugi {
-class xml_node;
-} // namespace pugi
-
-namespace xlnt {
-
-class border;
-class fill;
-class font;
-class named_style;
-class number_format;
-class style;
-class zip_file;
-    
-class style_reader
-{
-public:
-    style_reader(workbook &wb);
-    
-    void read_styles(zip_file &archive);
-    
-    const std::vector<style> &get_styles() const { return styles_; }
-    
-    const std::vector<border> &get_borders() const { return borders_; }
-    const std::vector<fill> &get_fills() const { return fills_; }
-    const std::vector<font> &get_fonts() const { return fonts_; }
-    const std::vector<number_format> &get_number_formats() const { return number_formats_; }
-    const std::vector<std::string> &get_colors() const { return colors_; }
-    
-private:
-    style read_style(pugi::xml_node stylesheet_node, pugi::xml_node xf_node);
-    
-    void read_borders(pugi::xml_node borders_node);
-    void read_fills(pugi::xml_node fills_node);
-    void read_fonts(pugi::xml_node fonts_node);
-    void read_number_formats(pugi::xml_node num_fmt_node);
-    void read_colors(pugi::xml_node colors_node);
-    
-    void read_dxfs();
-    void read_named_styles(pugi::xml_node named_styles_node);
-    void read_style_names();
-    void read_cell_styles();
-    void read_xfs();
-    void read_style_table();
-
-    workbook wb_;
-    
-    std::vector<style> styles_;
-    
-    std::vector<std::string> colors_;
-    std::vector<border> borders_;
-    std::vector<fill> fills_;
-    std::vector<font> fonts_;
-    std::vector<number_format> number_formats_;
-};
-
-} // namespace xlnt
diff --git a/include/xlnt/writer/chart_writer.hpp b/include/xlnt/s11n/comment_serializer.hpp
similarity index 76%
rename from include/xlnt/writer/chart_writer.hpp
rename to include/xlnt/s11n/comment_serializer.hpp
index 0a196c0c..6ce09934 100644
--- a/include/xlnt/writer/chart_writer.hpp
+++ b/include/xlnt/s11n/comment_serializer.hpp
@@ -23,43 +23,28 @@
 // @author: see AUTHORS file
 #pragma once
 
-#include <string>
-#include <unordered_map>
 #include <vector>
 
-#include "charts/chart.h"
+#include <xlnt/cell/comment.hpp>
+#include <xlnt/worksheet/worksheet.hpp>
 
 namespace xlnt {
 
-class chart_writer
+class xml_node;
+    
+class comment_serializer
 {
-
-};
-
-class pie_chart_writer : public chart_writer
-{
-
-};
-
-class pie_chart_writer : public chart_writer
-{
-
-};
-
-class pie_chart_writer : public chart_writer
-{
-
-};
-
-class pie_chart_writer : public chart_writer
-{
-
-};
-
-class chart_writer_factory
-{
-public:
-    static std::unique_ptr<chart_writer> create_writer(chart c);
+    comment_serializer(worksheet sheet);
+    
+    void read_comments(const xml_node &xml);
+    void read_comments_vml(const xml_node &xml);
+    
+    xml_node write_comments();
+    xml_node write_comments_vml();
+    
+private:
+    worksheet sheet_;
+    std::vector<comment> comments_;
 };
 
 } // namespace xlnt
diff --git a/include/xlnt/reader/excel_reader.hpp b/include/xlnt/s11n/excel_serializer.hpp
similarity index 51%
rename from include/xlnt/reader/excel_reader.hpp
rename to include/xlnt/s11n/excel_serializer.hpp
index 4c46d1e2..3eb4628f 100644
--- a/include/xlnt/reader/excel_reader.hpp
+++ b/include/xlnt/s11n/excel_serializer.hpp
@@ -23,23 +23,53 @@
 // @author: see AUTHORS file
 #pragma once
 
-#include <iostream>
+#include <cstdint>
+#include <ostream>
 #include <string>
 #include <vector>
 
+#include <xlnt/common/zip_file.hpp>
+
 namespace xlnt {
     
 class workbook;
 
-class excel_reader
+class excel_serializer
 {
 public:
-    static std::string CentralDirectorySignature();
+    static std::string central_directory_signature();
     static std::string repair_central_directory(const std::string &original);
+    
+    excel_serializer(workbook &wb);
+    
+    bool load_workbook(const std::string &filename, bool guess_types = false, bool data_only = false);
+    bool load_stream_workbook(std::istream &stream, bool guess_types = false, bool data_only = false);
+    bool load_virtual_workbook(const std::vector<std::uint8_t> &bytes, bool guess_types = false, bool data_only = false);
+    
+    bool save_workbook(workbook &wb, const std::string &filename, bool as_template = false);
+    bool save_virtual_workbook(xlnt::workbook &wb, std::vector<std::uint8_t> &bytes, bool as_template = false);
+    bool save_stream_workbook(xlnt::workbook &wb, std::ostream &stream, bool as_template = false);
+    
+private:
+    void read_data(bool guess_types, bool data_only);
+    void read_shared_strings();
+    void read_images();
+    void read_charts();
+    void read_chartsheets();
+    void read_worksheets();
+    void read_external_links();
+    
+    void write_data(bool as_template);
+    void write_shared_strings();
+    void write_images();
+    void write_charts();
+    void write_chartsheets();
+    void write_worksheets();
+    void write_external_links();
 
-    static workbook load_workbook(std::istream &stream, bool guess_types = false, bool data_only = false);
-    static workbook load_workbook(const std::string &filename, bool guess_types = false, bool data_only = false);
-    static workbook load_workbook(const std::vector<std::uint8_t> &bytes, bool guess_types = false, bool data_only = false);
+    workbook &wb_;
+    std::vector<std::string> shared_strings_;
+    zip_file archive_;
 };
 
 } // namespace xlnt
diff --git a/include/xlnt/s11n/manifest_serializer.hpp b/include/xlnt/s11n/manifest_serializer.hpp
new file mode 100644
index 00000000..41697c89
--- /dev/null
+++ b/include/xlnt/s11n/manifest_serializer.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <string>
+
+namespace xlnt {
+    
+class manifest;
+class workbook;
+class xml_document;
+class zip_file;
+
+class manifest_serializer
+{
+public:
+    manifest_serializer(manifest &m);
+    
+    bool read_mainfest(const xml_document &xml);
+    bool write_manifest(xml_document &xml);
+    
+private:
+    manifest &manifest_;
+};
+    
+}; // namespace xlnt
diff --git a/include/xlnt/s11n/relationship_serializer.hpp b/include/xlnt/s11n/relationship_serializer.hpp
new file mode 100644
index 00000000..8df03c90
--- /dev/null
+++ b/include/xlnt/s11n/relationship_serializer.hpp
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace xlnt {
+    
+class relationship;
+class xml_document;
+
+class relationship_serializer
+{
+    bool read_relationships(const xml_document &xml, const std::string &dir, std::vector<relationship> &relationships);
+    bool write_relationships(const std::vector<relationship> &relationships, const std::string &dir, xml_document &xml);
+};
+    
+} // namespace xlnt
diff --git a/include/xlnt/reader/shared_strings_reader.hpp b/include/xlnt/s11n/shared_strings_serializer.hpp
similarity index 85%
rename from include/xlnt/reader/shared_strings_reader.hpp
rename to include/xlnt/s11n/shared_strings_serializer.hpp
index 0c575c75..a528d848 100644
--- a/include/xlnt/reader/shared_strings_reader.hpp
+++ b/include/xlnt/s11n/shared_strings_serializer.hpp
@@ -28,15 +28,13 @@
 
 namespace xlnt {
     
-class zip_file;
+class xml_document;
 
-class shared_strings_reader
+class shared_strings_serializer
 {
 public:
-    std::vector<std::string> read_strings(zip_file &archive);
-    void read_string_table(const std::string &xml_source);
-    std::string get_string();
-    std::string get_text();
+    bool read_strings(const xml_document &xml, std::vector<std::string> &strings);
+    bool write_strings(const std::vector<std::string> &strings, xml_document &xml);
 };
 
 } // namespace xlnt
diff --git a/include/xlnt/s11n/style_serializer.hpp b/include/xlnt/s11n/style_serializer.hpp
new file mode 100644
index 00000000..2895520e
--- /dev/null
+++ b/include/xlnt/s11n/style_serializer.hpp
@@ -0,0 +1,255 @@
+// Copyright (c) 2015 Thomas Fussell
+// Copyright (c) 2010-2015 openpyxl
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE
+//
+// @license: http://www.opensource.org/licenses/mit-license.php
+// @author: see AUTHORS file
+#pragma once
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include <xlnt/workbook/workbook.hpp>
+
+namespace xlnt {
+
+class alignment;
+class border;
+class color;
+class conditional_format;
+class fill;
+class font;
+class named_style;
+class number_format;
+class protection;
+class side;
+class style;
+class xml_document;
+class xml_node;
+    
+/// <summary>
+/// Reads and writes xl/styles.xml from/to an associated workbook.
+/// </summary>
+class style_serializer
+{
+public:
+    /// <summary>
+    /// Construct a style_serializer which can write styles.xml based on wb or populate wb
+    /// with styles from an existing styles.xml.
+    style_serializer(workbook &wb);
+    
+    /// <summary>
+    /// Load all styles from xml_document into workbook given in constructor.
+    /// </summary>
+    bool read_stylesheet(const xml_document &xml);
+    
+    /// <summary>
+    /// Populate parameter xml with an XML tree representing the styles contained in the workbook
+    /// given in the constructor.
+    /// </summary>
+    bool write_stylesheet(xml_document &xml) const;
+    
+private:
+    /// <summary>
+    /// Read a single style from the given node. In styles.xml, this is an "xf" element.
+    /// A style has an optional border id, fill id, font id, and number format id where
+    /// each id is an index in the corresponding list of borders, etc. A style also has
+    /// optional alignment and protection children. A style also defines whether each of
+    /// these is "applied". For example, a style with a defined font id, font=# but with
+    /// "applyFont=0" will not use the font in formatting.
+    /// </summary>
+    style read_style(const xml_node &style_node) const;
+    
+    /// <summary>
+    /// Read and return an alignment from alignment_node.
+    /// </summary>
+    alignment read_alignment(const xml_node &alignment_node) const;
+    
+    /// <summary>
+    /// Read and return a border side from side_node.
+    /// </summary>
+    side read_side(const xml_node &side_node) const;
+    
+    /// <summary>
+    /// Read all borders from borders_node and add them to workbook.
+    /// Return true on success.
+    /// </summary>
+    bool read_borders(const xml_node &borders_node);
+    
+    /// <summary>
+    /// Read and return a border from border_node.
+    /// </summary>
+    border read_border(const xml_node &border_node) const;
+    
+    /// <summary>
+    /// Read all fills from fills_node and add them to workbook.
+    /// Return true on success.
+    /// </summary>
+    bool read_fills(const xml_node &fills_node);
+    
+    /// <summary>
+    /// Read and return a fill from fill_node.
+    /// </summary>
+    fill read_fill(const xml_node &fill_node) const;
+    
+    /// <summary>
+    /// Read all fonts from fonts_node and add them to workbook.
+    /// Return true on success.
+    /// </summary>
+    bool read_fonts(const xml_node &fonts_node);
+    
+    /// <summary>
+    /// Read and return a font from font_node.
+    /// </summary>
+    font read_font(const xml_node &font_node) const;
+    
+    /// <summary>
+    /// Read all borders from number_formats_node and add them to workbook.
+    /// Return true on success.
+    /// </summary>
+    bool read_number_formats(const xml_node &number_formats_node);
+    
+    /// <summary>
+    /// Read and return a number format from number_format_node.
+    /// </summary>
+    number_format read_number_format(const xml_node &number_format_node) const;
+    
+    /// <summary>
+    /// Read and return a protection from protection_node.
+    /// </summary>
+    protection read_protection(const xml_node &protection_node) const;
+    
+    /// <summary>
+    /// Read all colors from colors_node and add them to workbook.
+    /// Return true on success.
+    /// </summary>
+    bool read_colors(const xml_node &colors_node);
+    
+    /// <summary>
+    /// Read and return all indexed colors from indexed_colors_node.
+    /// </summary>
+    std::vector<color> read_indexed_colors(const xml_node &indexed_colors_node) const;
+    
+    /// <summary>
+    /// Read and return a color from color_node.
+    /// </summary>
+    color read_color(const xml_node &color_node) const;
+    
+    /// <summary>
+    /// Read and return a conditional format, dxf, from conditional_format_node.
+    /// </summary>
+    conditional_format read_conditional_format(const xml_node &conditional_formats_node) const;
+    
+    /// <summary>
+    /// Read all named styles from named_style_node and cell_styles_node and add them to workbook.
+    /// Return true on success.
+    /// </summary>
+    bool read_named_styles(const xml_node &named_styles_node);
+    
+    /// <summary>
+    /// Read and return a pair containing a name and corresponding style from named_style_node.
+    /// </summary>
+    std::pair<std::string, style> read_named_style(const xml_node &named_style_node) const;
+    
+    /// <summary>
+    /// Build and return an xml tree representing alignment_.
+    /// </summary>
+    xml_node write_alignment(const alignment &alignment_) const;
+    
+    /// <summary>
+    /// Build and return an xml tree representing border_.
+    /// </summary>
+    xml_node write_border(const border &border_) const;
+    
+    /// <summary>
+    /// Build an xml tree representing all borders in workbook into borders_node.
+    /// Returns true on success.
+    /// </summary>
+    bool write_borders(xml_node &borders_node) const;
+    
+    /// <summary>
+    /// Build and return an xml tree representing fill_.
+    /// </summary>
+    xml_node write_fill(const fill &fill_) const;
+    
+    /// <summary>
+    /// Build an xml tree representing all fills in workbook into fills_node.
+    /// Returns true on success.
+    /// </summary>
+    bool write_fills(xml_node &fills_node) const;
+    
+    /// <summary>
+    /// Build and return an xml tree representing font_.
+    /// </summary>
+    xml_node write_font(const font &font_) const;
+    
+    /// <summary>
+    /// Build an xml tree representing all fonts in workbook into fonts_node.
+    /// Returns true on success.
+    /// </summary>
+    bool write_fonts(xml_node &fonts_node) const;
+    
+    /// <summary>
+    /// Build and return an xml tree representing number_format_.
+    /// </summary>
+    xml_node write_number_format(const number_format &number_format_) const;
+    
+    /// <summary>
+    /// Build an xml tree representing all number formats in workbook into number_formats_node.
+    /// Returns true on success.
+    /// </summary>
+    bool write_number_formats(xml_node &fonts_node) const;
+    
+    /// <summary>
+    /// Build and return two xml trees, first=cell style and second=named style, representing named_style_.
+    /// </summary>
+    std::pair<xml_node, xml_node> write_named_style(const named_style &named_style_) const;
+    
+    /// <summary>
+    /// Build an xml tree representing all named styles in workbook into named_styles_node and cell_styles_node.
+    /// Returns true on success.
+    /// </summary>
+    void write_named_styles(xml_node &named_styles_node, xml_node &cell_styles_node) const;
+    
+    /// <summary>
+    /// Build an xml tree representing the given style into style_node.
+    /// Returns true on success.
+    /// </summary>
+    bool write_style(const style &style_, xml_node &style_node) const;
+    
+    /// <summary>
+    /// Build and return an xml tree representing conditional_format_.
+    /// </summary>
+    xml_node write_conditional_format(const conditional_format &conditional_format_) const;
+    
+    /// <summary>
+    /// Build an xml tree representing all conditional formats in workbook into conditional_formats_node.
+    /// Returns true on success.
+    /// </summary>
+    bool write_conditional_formats(xml_node &conditional_formats_node) const;
+    
+    /// <summary>
+    /// Set in the constructor, this workbook is used as the source or target for all writing or reading, respectively.
+    /// </summary>
+    workbook &wb_;
+};
+
+} // namespace xlnt
diff --git a/include/xlnt/writer/theme_writer.hpp b/include/xlnt/s11n/theme_serializer.hpp
similarity index 90%
rename from include/xlnt/writer/theme_writer.hpp
rename to include/xlnt/s11n/theme_serializer.hpp
index 0f607771..6db65bc5 100644
--- a/include/xlnt/writer/theme_writer.hpp
+++ b/include/xlnt/s11n/theme_serializer.hpp
@@ -27,7 +27,11 @@
 
 namespace xlnt {
 
-std::string write_theme();
-//void write_theme(const theme &t);
+class theme_serializer
+{
+public:
+    theme read_theme(const xml_document &xml);
+    xml_document write_theme(const theme &theme_);
+};
 
 } // namespace xlnt
diff --git a/include/xlnt/reader/workbook_reader.hpp b/include/xlnt/s11n/workbook_serializer.hpp
similarity index 62%
rename from include/xlnt/reader/workbook_reader.hpp
rename to include/xlnt/s11n/workbook_serializer.hpp
index 1e22dbf2..1400d18e 100644
--- a/include/xlnt/reader/workbook_reader.hpp
+++ b/include/xlnt/s11n/workbook_serializer.hpp
@@ -23,23 +23,44 @@
 // @author: see AUTHORS file
 #pragma once
 
-#include <cstdint>
 #include <string>
 #include <vector>
 
 namespace xlnt {
 
 class document_properties;
+class manifest;
 class relationship;
+class worksheet;
 class workbook;
 class zip_file;
+class xml_document;
     
-std::vector<std::pair<std::string, std::string>> read_content_types(zip_file &archive);
-std::string determine_document_type(const std::vector<std::pair<std::string, std::string>> &override_types);
-document_properties read_properties_core(const std::string &xml_string);
+class workbook_serializer
+{
+public:
+    workbook_serializer(workbook &wb);
     
-std::vector<std::pair<std::string,std::string>> read_sheets(zip_file &archive);
-std::vector<std::pair<std::string, std::string>> detect_worksheets(zip_file &archive);
-std::vector<relationship> read_relationships(zip_file &content, const std::string &filename);
+    void read_workbook(const xml_document &xml);
+    void read_properties_app(const xml_document &xml);
+    void read_properties_core(const xml_document &xml);
+    
+    xml_document write_workbook() const;
+    xml_document write_properties_app() const;
+    xml_document write_properties_core() const;
+    
+private:
+    //workbook_view, sheets, sheet, defined_names
+    std::string determine_document_type(const manifest &manifest_);
+    
+    using string_pair = std::pair<std::string, std::string>;
+    
+    std::vector<string_pair> read_sheets(zip_file &archive);
+    std::vector<string_pair> detect_worksheets(zip_file &archive);
+
+    std::string write_defined_names(const workbook &wb);
+    
+    workbook &wb_;
+};
 
 } // namespace xlnt
diff --git a/include/xlnt/reader/worksheet_reader.hpp b/include/xlnt/s11n/worksheet_serializer.hpp
similarity index 72%
rename from include/xlnt/reader/worksheet_reader.hpp
rename to include/xlnt/s11n/worksheet_serializer.hpp
index 455e55f3..31eacd34 100644
--- a/include/xlnt/reader/worksheet_reader.hpp
+++ b/include/xlnt/s11n/worksheet_serializer.hpp
@@ -26,13 +26,27 @@
 #include <string>
 #include <vector>
 
+#include <xlnt/worksheet/worksheet.hpp>
+
 namespace xlnt {
     
 class relationship;
 class workbook;
-class zip_file;
+class worksheet;
+class xml_document;
+class xml_node;
 
-void read_worksheet(worksheet ws, zip_file &archive, const relationship &rel, const std::vector<std::string> &shared_strings);
-std::string read_dimension(const std::string &xml_string);
+class worksheet_serializer
+{
+public:
+    worksheet_serializer(worksheet sheet);
+    
+    bool read_worksheet(const xml_document &xml, const std::vector<std::string> &shared_strings, const relationship &rel,  worksheet ws);
+    std::string read_dimension(const xml_node &dimension_node);
+    bool write_worksheet(const worksheet ws, const std::vector<std::string> &string_table, xml_document &xml);
+    
+private:
+    worksheet sheet_;
+};
 
 } // namespace xlnt
diff --git a/include/xlnt/s11n/xml_document.hpp b/include/xlnt/s11n/xml_document.hpp
new file mode 100644
index 00000000..b6dd3bfd
--- /dev/null
+++ b/include/xlnt/s11n/xml_document.hpp
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include <xlnt/s11n/xml_node.hpp>
+
+namespace xlnt {
+
+class xml_document
+{
+public:
+    void set_encoding(const std::string &encoding);
+    void add_namespace(const std::string &id, const std::string &uri);
+    
+    xml_node &root();
+    const xml_node &root() const;
+    
+private:
+    xml_node root_;
+    std::string encoding_;
+    std::vector<string_pair> namespaces_;
+};
+
+} // namespace xlnt
diff --git a/include/xlnt/s11n/xml_node.hpp b/include/xlnt/s11n/xml_node.hpp
new file mode 100644
index 00000000..8534b084
--- /dev/null
+++ b/include/xlnt/s11n/xml_node.hpp
@@ -0,0 +1,42 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace xlnt {
+
+using string_pair = std::pair<std::string, std::string>;
+
+class xml_node
+{
+public:
+    xml_node();
+    explicit xml_node(const std::string &name);
+    
+    std::string get_name() const;
+    void set_name(const std::string &name);
+    
+    bool has_text() const;
+    std::string get_text() const;
+    void set_text(const std::string &text);
+    
+    const std::vector<xml_node> &get_children() const;
+    bool has_child(const std::string &child_name) const;
+    const xml_node &get_child(const std::string &child_name) const;
+    xml_node &add_child(const xml_node &child);
+    xml_node &add_child(const std::string &child_name);
+    
+    const std::vector<string_pair> &get_attributes() const;
+    bool has_attribute(const std::string &attribute_name) const;
+    std::string get_attribute(const std::string &attribute_name) const;
+    void add_attribute(const std::string &name, const std::string &value);
+    
+private:
+    std::string name_;
+    bool has_text_ = false;
+    std::string text_;
+    std::vector<string_pair> attributes_;
+    std::vector<xml_node> children_;
+};
+
+} // namespace xlnt
diff --git a/include/xlnt/s11n/xml_serializer.hpp b/include/xlnt/s11n/xml_serializer.hpp
new file mode 100644
index 00000000..0d89d37d
--- /dev/null
+++ b/include/xlnt/s11n/xml_serializer.hpp
@@ -0,0 +1,16 @@
+#pragma once
+
+#include <string>
+
+namespace xlnt {
+    
+class xml_document;
+
+class xml_serializer
+{
+public:
+    static std::string serialize(const xml_document &xml);
+    static xml_document deserialize(const std::string &xml_string);
+};
+
+} // namespace xlnt
diff --git a/include/xlnt/styles/color.hpp b/include/xlnt/styles/color.hpp
index 358ec413..cf7c1123 100644
--- a/include/xlnt/styles/color.hpp
+++ b/include/xlnt/styles/color.hpp
@@ -23,6 +23,10 @@
 // @author: see AUTHORS file
 #pragma once
 
+#include <string>
+
+#include <xlnt/common/hash_combine.hpp>
+
 namespace xlnt {
 
 class color
@@ -57,12 +61,6 @@ public:
     {
     }
     
-    bool operator==(const color &other) const
-    {
-        if(type_ != other.type_) return false;
-        return index_ == other.index_;
-    }
-    
     void set_auto(int auto_index)
     {
         type_ = type::auto_;
@@ -126,6 +124,27 @@ public:
         return rgb_string_;
     }
     
+    std::size_t hash() const
+    {
+        auto seed = static_cast<std::size_t>(type_);
+        
+        if(type_ != type::rgb)
+        {
+            hash_combine(seed, index_);
+        }
+        else
+        {
+            hash_combine(seed, rgb_string_);
+        }
+        
+        return seed;
+    }
+    
+    bool operator==(const color &other) const
+    {
+        return hash() == other.hash();
+    }
+    
 private:
     type type_ = type::indexed;
     int index_ = 0;
diff --git a/include/xlnt/styles/side.hpp b/include/xlnt/styles/side.hpp
index b59ce306..4d4cb5ac 100644
--- a/include/xlnt/styles/side.hpp
+++ b/include/xlnt/styles/side.hpp
@@ -25,7 +25,7 @@
 
 #include <cstddef>
 
-#include "../common/hash_combine.hpp"
+#include <xlnt/styles/color.hpp>
 
 namespace xlnt {
 
@@ -73,8 +73,7 @@ public:
         
         if(color_assigned_)
         {
-            hash_combine(seed, static_cast<std::size_t>(color_type_));
-            hash_combine(seed, color_);
+            hash_combine(seed, color_.hash());
         }
         
         return seed;
@@ -85,12 +84,7 @@ public:
         return style_;
     }
     
-    color_type get_color_type() const
-    {
-        return color_type_;
-    }
-    
-    std::size_t get_color() const
+    color get_color() const
     {
         return color_;
     }
@@ -107,7 +101,7 @@ public:
     
     bool operator==(const side &other) const
     {
-        return other.style_ == style_ && color_type_ == other.color_type_ && color_ == other.color_;
+        return other.style_ == style_ && color_ == other.color_;
     }
     
     void set_border_style(border_style bs)
@@ -116,19 +110,17 @@ public:
         style_ = bs;
     }
     
-    void set_color(color_type type, std::size_t color)
+    void set_color(color new_color)
     {
         color_assigned_ = true;
-        color_type_ = type;
-        color_ = color;
+        color_ = new_color;
     }
     
 private:
     bool style_assigned_ = false;
     border_style style_ = border_style::none;
     bool color_assigned_ = false;
-    color_type color_type_ = color_type::indexed;
-    std::size_t color_ = 0;
+    color color_ = color::black;
 };
     
 } // namespace xlnt
diff --git a/include/xlnt/styles/style.hpp b/include/xlnt/styles/style.hpp
index 01cbe63b..b84202a7 100644
--- a/include/xlnt/styles/style.hpp
+++ b/include/xlnt/styles/style.hpp
@@ -72,8 +72,7 @@ public:
     }
     
 private:
-    friend class style_reader;
-    friend class style_writer;
+    friend class style_serializer;
     friend class workbook;
     
     std::size_t id_;
diff --git a/include/xlnt/workbook/manifest.hpp b/include/xlnt/workbook/manifest.hpp
new file mode 100644
index 00000000..061ad655
--- /dev/null
+++ b/include/xlnt/workbook/manifest.hpp
@@ -0,0 +1,60 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+namespace xlnt {
+    
+class default_type
+{
+public:
+    default_type();
+    default_type(const std::string &extension, const std::string &content_type);
+    default_type(const default_type &other);
+    default_type &operator=(const default_type &other);
+    
+    std::string get_extension() const { return extension_; }
+    std::string get_content_type() const { return content_type_; }
+    
+private:
+    std::string extension_;
+    std::string content_type_;
+};
+
+class override_type
+{
+public:
+    override_type();
+    override_type(const std::string &extension, const std::string &content_type);
+    override_type(const override_type &other);
+    override_type &operator=(const override_type &other);
+    
+    std::string get_part_name() const { return part_name_; }
+    std::string get_content_type() const { return content_type_; }
+    
+private:
+    std::string part_name_;
+    std::string content_type_;
+};
+
+class manifest
+{
+public:
+    void add_default_type(const std::string &extension, const std::string &content_type);
+    void add_override_type(const std::string &part_name, const std::string &content_type);
+    
+    const std::vector<default_type> &get_default_types() const { return default_types_; }
+    const std::vector<override_type> &get_override_types() const { return override_types_; }
+    
+    bool has_default_type(const std::string &extension) const;
+    bool has_override_type(const std::string &part_name) const;
+    
+    std::string get_default_type(const std::string &extension) const;
+    std::string get_override_type(const std::string &part_name) const;
+    
+private:
+    std::vector<default_type> default_types_;
+    std::vector<override_type> override_types_;
+};
+    
+} // namespace xlnt
\ No newline at end of file
diff --git a/include/xlnt/workbook/theme.hpp b/include/xlnt/workbook/theme.hpp
new file mode 100644
index 00000000..2025fe31
--- /dev/null
+++ b/include/xlnt/workbook/theme.hpp
@@ -0,0 +1,10 @@
+#pragma once
+
+namespace xlnt {
+
+class theme
+{
+    
+};
+    
+} // namespace xlnt
diff --git a/include/xlnt/workbook/workbook.hpp b/include/xlnt/workbook/workbook.hpp
index 9a674682..c5ea9518 100644
--- a/include/xlnt/workbook/workbook.hpp
+++ b/include/xlnt/workbook/workbook.hpp
@@ -29,7 +29,7 @@
 #include <utility>
 #include <vector>
 
-#include "../common/relationship.hpp"
+#include <xlnt/common/relationship.hpp>
 
 namespace xlnt {
 
@@ -40,6 +40,7 @@ class document_properties;
 class drawing;
 class fill;
 class font;
+class manifest;
 class named_range;
 class number_format;
 class pattern_fill;
@@ -242,6 +243,9 @@ public:
     const style &get_style(std::size_t style_id) const;
     std::size_t add_style(const style &style_);
     
+    manifest &get_manifest();
+    const manifest &get_manifest() const;
+    
 private:
     friend class worksheet;
     std::shared_ptr<detail::workbook_impl> d_;
diff --git a/include/xlnt/worksheet/worksheet.hpp b/include/xlnt/worksheet/worksheet.hpp
index 9a5cab7d..9be5f5a5 100644
--- a/include/xlnt/worksheet/worksheet.hpp
+++ b/include/xlnt/worksheet/worksheet.hpp
@@ -262,8 +262,8 @@ public:
     const range operator()(const cell_reference &top_left, const cell_reference &bottom_right) const;
     
     // page
-    page_setup &get_page_setup();
-    margins &get_page_margins();
+    const page_setup &get_page_setup() const;
+    const margins &get_page_margins() const;
     
     // auto filter
     range_reference get_auto_filter() const;
diff --git a/include/xlnt/writer/comment_writer.hpp b/include/xlnt/writer/comment_writer.hpp
deleted file mode 100644
index 8d3d4514..00000000
--- a/include/xlnt/writer/comment_writer.hpp
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright (c) 2015 Thomas Fussell
-// Copyright (c) 2010-2015 openpyxl
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE
-//
-// @license: http://www.opensource.org/licenses/mit-license.php
-// @author: see AUTHORS file
-#pragma once
-
-namespace xlnt {
-
-class comment_writer
-{
-
-};
-
-} // namespace xlnt
diff --git a/include/xlnt/writer/excel_writer.hpp b/include/xlnt/writer/excel_writer.hpp
deleted file mode 100644
index e26973ed..00000000
--- a/include/xlnt/writer/excel_writer.hpp
+++ /dev/null
@@ -1,56 +0,0 @@
-// Copyright (c) 2015 Thomas Fussell
-// Copyright (c) 2010-2015 openpyxl
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE
-//
-// @license: http://www.opensource.org/licenses/mit-license.php
-// @author: see AUTHORS file
-#pragma once
-
-#include <string>
-#include <vector>
-
-namespace xlnt {
-
-class workbook;
-class zip_file;
-
-class excel_writer
-{
-public:
-    excel_writer(workbook &wb);
-    
-    void save(const std::string &filename, bool as_template);
-    
-    void write_data(zip_file &archive, bool as_template);
-    void write_shared_strings(zip_file &archive, const std::vector<std::string> &shared_strings);
-    void write_images(zip_file &archive);
-    void write_charts(zip_file &archive);
-    void write_chartsheets(zip_file &archive);
-    void write_worksheets(zip_file &archive, const std::vector<std::string> &shared_strings);
-    void write_external_links(zip_file &archive);
-    
-private:
-    workbook wb_;
-};
-    
-bool save_workbook(workbook &wb, const std::string &filename, bool as_template = false);
-std::vector<std::uint8_t> save_virtual_workbook(xlnt::workbook &wb, bool as_template = false);
-
-} // namespace xlnt
diff --git a/include/xlnt/writer/manifest_writer.hpp b/include/xlnt/writer/manifest_writer.hpp
deleted file mode 100644
index 6c7721b4..00000000
--- a/include/xlnt/writer/manifest_writer.hpp
+++ /dev/null
@@ -1,11 +0,0 @@
-#pragma once
-
-#include <string>
-
-namespace xlnt {
-    
-class workbook;
-
-std::string write_content_types(const workbook &wb, bool as_template = false);
-    
-};
diff --git a/include/xlnt/writer/relationship_writer.hpp b/include/xlnt/writer/relationship_writer.hpp
deleted file mode 100644
index 568ad400..00000000
--- a/include/xlnt/writer/relationship_writer.hpp
+++ /dev/null
@@ -1,12 +0,0 @@
-#pragma once
-
-#include <string>
-#include <vector>
-
-namespace xlnt {
-    
-class relationship;
- 
-std::string write_relationships(const std::vector<relationship> &relationships, const std::string &dir);
-    
-} // namespace xlnt
diff --git a/include/xlnt/writer/shared_strings_writer.hpp b/include/xlnt/writer/shared_strings_writer.hpp
deleted file mode 100644
index 15b4ec82..00000000
--- a/include/xlnt/writer/shared_strings_writer.hpp
+++ /dev/null
@@ -1,33 +0,0 @@
-// Copyright (c) 2015 Thomas Fussell
-// Copyright (c) 2010-2015 openpyxl
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE
-//
-// @license: http://www.opensource.org/licenses/mit-license.php
-// @author: see AUTHORS file
-#pragma once
-
-namespace xlnt {
-
-class string_writer
-{
-
-};
-
-} // namespace xlnt
diff --git a/include/xlnt/writer/style_writer.hpp b/include/xlnt/writer/style_writer.hpp
deleted file mode 100644
index 500a6ed1..00000000
--- a/include/xlnt/writer/style_writer.hpp
+++ /dev/null
@@ -1,61 +0,0 @@
-// Copyright (c) 2015 Thomas Fussell
-// Copyright (c) 2010-2015 openpyxl
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE
-//
-// @license: http://www.opensource.org/licenses/mit-license.php
-// @author: see AUTHORS file
-#pragma once
-
-#include <array>
-#include <string>
-#include <unordered_map>
-#include <vector>
-
-#include "../styles/style.hpp"
-
-namespace xlnt {
-
-class workbook;
-
-class style_writer
-{
-public:
-    style_writer(workbook &wb);
-    style_writer(const style_writer &);
-    style_writer &operator=(const style_writer &);
-    
-    std::string write_table() const;
-    std::string write_number_formats();
-    
-private:
-    std::vector<style> get_style_list(const workbook &wb) const;
-    std::unordered_map<int, std::string> write_fonts() const;
-    std::unordered_map<int, std::string> write_fills() const;
-    std::unordered_map<int, std::string> write_borders() const;
-    void write_cell_style_xfs();
-    void write_cell_xfs();
-    void write_cell_style();
-    void write_dxfs();
-    void write_table_styles();
-    
-    workbook &wb_;
-};
-    
-} // namespace xlnt
diff --git a/include/xlnt/writer/workbook_writer.hpp b/include/xlnt/writer/workbook_writer.hpp
deleted file mode 100644
index 7a53a810..00000000
--- a/include/xlnt/writer/workbook_writer.hpp
+++ /dev/null
@@ -1,43 +0,0 @@
-// Copyright (c) 2015 Thomas Fussell
-// Copyright (c) 2010-2015 openpyxl
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE
-//
-// @license: http://www.opensource.org/licenses/mit-license.php
-// @author: see AUTHORS file
-#pragma once
-
-#include <string>
-#include <vector>
-
-#include <xlnt/writer/style_writer.hpp>
-
-namespace xlnt {
-
-std::string write_shared_strings(const std::vector<std::string> &string_table);
-std::string write_properties_core(const document_properties &prop);
-std::string write_worksheet_rels(worksheet ws);
-std::string write_theme();
-std::string write_properties_app(const workbook &wb);
-std::string write_root_rels(const workbook &wb);
-std::string write_workbook(const workbook &wb);
-std::string write_workbook_rels(const workbook &wb);
-std::string write_defined_names(const xlnt::workbook &wb);
-    
-} // namespace xlnt
diff --git a/include/xlnt/writer/worksheet_writer.hpp b/include/xlnt/writer/worksheet_writer.hpp
deleted file mode 100644
index 19f52843..00000000
--- a/include/xlnt/writer/worksheet_writer.hpp
+++ /dev/null
@@ -1,13 +0,0 @@
-#pragma once
-
-#include <string>
-#include <unordered_map>
-#include <vector>
-
-namespace xlnt {
-    
-class worksheet;
-
-std::string write_worksheet(worksheet ws, const std::vector<std::string> &string_table);
-    
-} // namespace xlnt
diff --git a/source/cell/cell.cpp b/source/cell/cell.cpp
index 761d9966..e69c01f5 100644
--- a/source/cell/cell.cpp
+++ b/source/cell/cell.cpp
@@ -799,15 +799,20 @@ std::string format_text(const std::string &text, const std::string &format)
 
 namespace xlnt {
     
-const std::unordered_map<std::string, int> cell::ErrorCodes =
+const std::unordered_map<std::string, int> cell::error_codes()
 {
-    {"#NULL!", 0},
-    {"#DIV/0!", 1},
-    {"#VALUE!", 2},
-    {"#REF!", 3},
-    {"#NAME?", 4},
-    {"#NUM!", 5},
-    {"#N/A!", 6}
+    static const std::unordered_map<std::string, int> codes =
+    {
+        {"#NULL!", 0},
+        {"#DIV/0!", 1},
+        {"#VALUE!", 2},
+        {"#REF!", 3},
+        {"#NAME?", 4},
+        {"#NUM!", 5},
+        {"#N/A!", 6}
+    };
+    
+    return codes;
 };
 
 cell::cell() : d_(nullptr)
@@ -1271,11 +1276,6 @@ void cell::set_data_type(type t)
     d_->type_ = t;
 }
 
-std::size_t cell::get_xf_index() const
-{
-    return d_->xf_index_;
-}
-
 const number_format &cell::get_number_format() const
 {
     static const number_format default_format;
@@ -1499,5 +1499,5 @@ calendar cell::get_base_date() const
 {
     return get_parent().get_parent().get_properties().excel_base_date;
 }
-
+    
 } // namespace xlnt
diff --git a/source/detail/cell_impl.cpp b/source/detail/cell_impl.cpp
index 7796b94a..0270fe14 100644
--- a/source/detail/cell_impl.cpp
+++ b/source/detail/cell_impl.cpp
@@ -22,7 +22,6 @@ cell_impl::cell_impl(worksheet_impl *parent, column_t column, row_t row)
       value_numeric_(0),
       has_hyperlink_(false),
       is_merged_(false),
-      xf_index_(0),
       has_style_(false),
       style_id_(0),
       comment_(nullptr)
diff --git a/source/detail/cell_impl.hpp b/source/detail/cell_impl.hpp
index e10ffee3..b46446c7 100644
--- a/source/detail/cell_impl.hpp
+++ b/source/detail/cell_impl.hpp
@@ -140,7 +140,7 @@ struct cell_impl
             type_ = cell::type::formula;
             value_string_.clear();
         }
-        else if(cell::ErrorCodes.find(s) != cell::ErrorCodes.end())
+        else if(cell::error_codes().find(s) != cell::error_codes().end())
         {
             type_ = cell::type::error;
         }
@@ -195,8 +195,6 @@ struct cell_impl
     
     bool is_merged_;
     
-    std::size_t xf_index_;
-    
     bool has_style_;
     std::size_t style_id_;
     
diff --git a/source/detail/workbook_impl.hpp b/source/detail/workbook_impl.hpp
index ad5e5d7c..9ba12776 100644
--- a/source/detail/workbook_impl.hpp
+++ b/source/detail/workbook_impl.hpp
@@ -23,7 +23,8 @@ struct workbook_impl
         borders_(other.borders_),
         fills_(other.fills_),
         fonts_(other.fonts_),
-        number_formats_(other.number_formats_)
+        number_formats_(other.number_formats_),
+        manifest_(other.manifest_)
     {
     }
     
@@ -45,6 +46,7 @@ struct workbook_impl
         fonts_ = other.fonts_;
         number_formats_ = other.number_formats_;
         colors_ = other.colors_;
+        manifest_ = other.manifest_;
         
         return *this;
     }
@@ -69,6 +71,7 @@ struct workbook_impl
     std::vector<font> fonts_;
     std::vector<number_format> number_formats_;
     
+    manifest manifest_;
 };
 
 } // namespace detail
diff --git a/source/reader/shared_strings_reader.cpp b/source/reader/shared_strings_reader.cpp
deleted file mode 100644
index 252be95f..00000000
--- a/source/reader/shared_strings_reader.cpp
+++ /dev/null
@@ -1,38 +0,0 @@
-#include <xlnt/common/zip_file.hpp>
-#include <xlnt/reader/shared_strings_reader.hpp>
-
-#include "detail/include_pugixml.hpp"
-
-namespace xlnt {
-
-std::vector<std::string> shared_strings_reader::read_strings(zip_file &archive)
-{
-    static const std::string shared_strings_filename = "xl/sharedStrings.xml";
-    
-    if(!archive.has_file(shared_strings_filename))
-    {
-        return { };
-    }
-    
-    pugi::xml_document doc;
-    doc.load(archive.read(shared_strings_filename).c_str());
-    
-    auto root_node = doc.child("sst");
-    int unique_count = root_node.attribute("uniqueCount").as_int();
- 
-    std::vector<std::string> shared_strings;
-    
-    for(auto si_node : root_node)
-    {
-        shared_strings.push_back(si_node.child("t").text().as_string());
-    }
-    
-    if(unique_count != (int)shared_strings.size())
-    {
-        throw std::runtime_error("counts don't match");
-    }
-    
-    return shared_strings;
-}
-
-} // namespace xlnt
diff --git a/source/reader/style_reader.cpp b/source/reader/style_reader.cpp
deleted file mode 100644
index 9b424b4d..00000000
--- a/source/reader/style_reader.cpp
+++ /dev/null
@@ -1,484 +0,0 @@
-#include <xlnt/common/zip_file.hpp>
-#include <xlnt/styles/border.hpp>
-#include <xlnt/styles/fill.hpp>
-#include <xlnt/styles/font.hpp>
-#include <xlnt/styles/named_style.hpp>
-#include <xlnt/styles/number_format.hpp>
-#include <xlnt/styles/style.hpp>
-#include <xlnt/reader/style_reader.hpp>
-
-#include "detail/include_pugixml.hpp"
-
-namespace xlnt {
-
-protection read_protection(pugi::xml_node node)
-{
-    auto prot_type_from_string = [](const std::string &type_string)
-    {
-        if(type_string == "true") return protection::type::protected_;
-        else if(type_string == "inherit") return protection::type::inherit;
-        return protection::type::unprotected;
-    };
- 
-    protection prot;
-    prot.set_locked(prot_type_from_string(node.attribute("locked").as_string()));
-    prot.set_hidden(prot_type_from_string(node.attribute("hidden").as_string()));
-    return prot;
-}
-    
-alignment read_alignment(pugi::xml_node node)
-{
-    alignment align;
-    
-    align.set_wrap_text(node.attribute("wrapText").as_bool());
-    
-    bool has_vertical = node.attribute("vertical") != nullptr;
-    std::string vertical = has_vertical ? node.attribute("vertical").as_string() : "";
-    
-    if(has_vertical)
-    {
-        if(vertical == "bottom")
-        {
-            align.set_vertical(alignment::vertical_alignment::bottom);
-        }
-        else if(vertical =="center")
-        {
-            align.set_vertical(alignment::vertical_alignment::center);
-        }
-        else if(vertical =="justify")
-        {
-            align.set_vertical(alignment::vertical_alignment::justify);
-        }
-        else if(vertical =="top")
-        {
-            align.set_vertical(alignment::vertical_alignment::top);
-        }
-        else
-        {
-            throw "unknown alignment";
-        }
-    }
-    
-    bool has_horizontal = node.attribute("horizontal") != nullptr;
-    std::string horizontal = has_horizontal ? node.attribute("horizontal").as_string() : "";
-    
-    if(has_horizontal)
-    {
-        if(horizontal == "left")
-        {
-            align.set_horizontal(alignment::horizontal_alignment::left);
-        }
-        else if(horizontal == "center")
-        {
-            align.set_horizontal(alignment::horizontal_alignment::center);
-        }
-        else if(horizontal == "center-continuous")
-        {
-            align.set_horizontal(alignment::horizontal_alignment::center_continuous);
-        }
-        else if(horizontal == "right")
-        {
-            align.set_horizontal(alignment::horizontal_alignment::right);
-        }
-        else if(horizontal == "justify")
-        {
-            align.set_horizontal(alignment::horizontal_alignment::justify);
-        }
-        else if(horizontal == "general")
-        {
-            align.set_horizontal(alignment::horizontal_alignment::general);
-        }
-        else
-        {
-            throw "unknown alignment";
-        }
-    }
-    
-    return align;
-}
-
-style style_reader::read_style(pugi::xml_node stylesheet_node, pugi::xml_node xf_node)
-{
-    style s;
-    
-    s.apply_number_format(xf_node.attribute("applyNumberFormat").as_bool());
-    s.number_format_id_ = xf_node.attribute("numFmtId").as_int();
-    
-    bool builtin_format = true;
-    
-    for(auto num_fmt : number_formats_)
-    {
-        if(num_fmt.get_id() == s.get_number_format_id())
-        {
-            s.number_format_ = num_fmt;
-            builtin_format = false;
-            break;
-        }
-    }
-    
-    if(builtin_format)
-    {
-        s.number_format_ = number_format::from_builtin_id(s.get_number_format_id());
-    }
-    
-    s.apply_font(xf_node.attribute("applyFont").as_bool());
-    s.font_id_ = xf_node.attribute("fontId") != nullptr ? xf_node.attribute("fontId").as_int() : 0;
-    s.font_ = fonts_[s.font_id_];
-    
-    s.apply_fill(xf_node.attribute("applyFill").as_bool());
-    s.fill_id_ = xf_node.attribute("fillId").as_int();
-    s.fill_ = fills_[s.fill_id_];
-    
-    s.apply_border(xf_node.attribute("applyBorder").as_bool());
-    s.border_id_ = xf_node.attribute("borderId").as_int();
-    s.border_ = borders_[s.border_id_];
-    
-    s.apply_protection(xf_node.attribute("protection") != nullptr);
-    
-    if(s.protection_apply_)
-    {
-        auto inline_protection = read_protection(xf_node.child("protection"));
-        s.protection_ = inline_protection;
-    }
-    
-    s.apply_alignment(xf_node.child("alignment") != nullptr);
-    
-    if(s.alignment_apply_)
-    {
-        auto inline_alignment = read_alignment(xf_node.child("alignment"));
-        s.alignment_ = inline_alignment;
-    }
-    
-    return s;
-}
-
-style_reader::style_reader(workbook &wb)
-{
-
-}
-
-void style_reader::read_styles(zip_file &archive)
-{
-    auto xml = archive.read("xl/styles.xml");
-    
-    pugi::xml_document doc;
-    doc.load_string(xml.c_str());
-    
-    auto root = doc.root();
-    auto stylesheet_node = root.child("styleSheet");
-    
-    read_borders(stylesheet_node.child("borders"));
-    read_fills(stylesheet_node.child("fills"));
-    read_fonts(stylesheet_node.child("fonts"));
-    read_number_formats(stylesheet_node.child("numFmts"));
-    
-    auto cell_xfs_node = stylesheet_node.child("cellXfs");
-    
-    for(auto xf_node : cell_xfs_node.children("xf"))
-    {
-        styles_.push_back(read_style(stylesheet_node, xf_node));
-        styles_.back().id_ = styles_.size() - 1;
-    }
-
-    read_colors(stylesheet_node.child("colors"));
-    
-    read_dxfs();
-    read_cell_styles();
-    read_named_styles(root.child("namedStyles"));
-}
-
-void style_reader::read_number_formats(pugi::xml_node num_fmts_node)
-{
-    for(auto num_fmt_node : num_fmts_node.children("numFmt"))
-    {
-        number_format nf;
-        
-        nf.set_format_string(num_fmt_node.attribute("formatCode").as_string());
-        if(nf.get_format_string() == "GENERAL")
-        {
-            nf.set_format_string("General");
-        }
-        nf.set_id(num_fmt_node.attribute("numFmtId").as_int());
-        
-        number_formats_.push_back(nf);
-    }
-}
-    
-void style_reader::read_dxfs()
-{
-    
-}
-
-void style_reader::read_fonts(pugi::xml_node fonts_node)
-{
-    for(auto font_node : fonts_node)
-    {
-        font new_font;
-        
-        new_font.set_size(font_node.child("sz").attribute("val").as_int());
-        new_font.set_name(font_node.child("name").attribute("val").as_string());
-        
-        if(font_node.child("color").attribute("theme") != nullptr)
-        {
-            new_font.set_color(color(color::type::theme, font_node.child("color").attribute("theme").as_ullong()));
-        }
-        else if(font_node.child("color").attribute("indexed") != nullptr)
-        {
-            new_font.set_color(color(color::type::indexed, font_node.child("color").attribute("indexed").as_ullong()));
-        }
-        
-        if(font_node.child("family") != nullptr)
-        {
-            new_font.set_family(font_node.child("family").attribute("val").as_int());
-        }
-        
-        if(font_node.child("scheme") != nullptr)
-        {
-            new_font.set_scheme(font_node.child("scheme").attribute("val").as_string());
-        }
-        
-        if(font_node.child("b") != nullptr)
-        {
-            new_font.set_bold(font_node.child("b").attribute("val").as_bool());
-        }
-        
-        if(font_node.child("strike") != nullptr)
-        {
-            new_font.set_strikethrough(font_node.child("strike").attribute("val").as_bool());
-        }
-        
-        if(font_node.child("i") != nullptr)
-        {
-            new_font.set_italic(font_node.child("i").attribute("val").as_bool());
-        }
-        
-        if(font_node.child("u") != nullptr)
-        {
-            std::string underline_string = font_node.child("u").attribute("val").as_string();
-            
-            if(underline_string == "single")
-            {
-                new_font.set_underline(font::underline_style::single);
-            }
-        }
-        
-        fonts_.push_back(new_font);
-    }
-}
-
-void style_reader::read_colors(pugi::xml_node colors_node)
-{
-    auto indexed_colors_node = colors_node.child("indexedColors");
-    
-    for(auto rgb_color_node : indexed_colors_node.children("rgbColor"))
-    {
-        colors_.push_back(rgb_color_node.attribute("rgb").as_string());
-    }
-}
-    
-void style_reader::read_fills(pugi::xml_node fills_node)
-{
-    auto pattern_fill_type_from_string = [](const std::string &fill_type)
-    {
-        if(fill_type == "none") return fill::pattern_type::none;
-        if(fill_type == "solid") return fill::pattern_type::solid;
-        if(fill_type == "gray125") return fill::pattern_type::gray125;
-        throw std::runtime_error("invalid fill type");
-    };
-    
-    for(auto fill_node : fills_node)
-    {
-        fill new_fill;
-        
-        if(fill_node.child("patternFill") != nullptr)
-        {
-            auto pattern_fill_node = fill_node.child("patternFill");
-            new_fill.set_type(fill::type::pattern);
-            std::string pattern_type_string = pattern_fill_node.attribute("patternType").as_string();
-            auto pattern_type = pattern_fill_type_from_string(pattern_type_string);
-            new_fill.set_pattern_type(pattern_type);
-            
-            auto bg_color_node = pattern_fill_node.child("bgColor");
-            
-            if(bg_color_node != nullptr)
-            {
-                if(bg_color_node.attribute("indexed") != nullptr)
-                {
-                    new_fill.set_background_color(color(color::type::indexed, bg_color_node.attribute("indexed").as_ullong()));
-                }
-                else if(bg_color_node.attribute("auto") != nullptr)
-                {
-                    new_fill.set_background_color(color(color::type::auto_, bg_color_node.attribute("auto").as_ullong()));
-                }
-                else if(bg_color_node.attribute("theme") != nullptr)
-                {
-                    new_fill.set_background_color(color(color::type::theme, bg_color_node.attribute("theme").as_ullong()));
-                }
-            }
-            
-            auto fg_color_node = pattern_fill_node.child("fgColor");
-            
-            if(fg_color_node != nullptr)
-            {
-                if(fg_color_node.attribute("indexed") != nullptr)
-                {
-                    new_fill.set_foreground_color(color(color::type::indexed, fg_color_node.attribute("indexed").as_ullong()));
-                }
-                else if(fg_color_node.attribute("auto") != nullptr)
-                {
-                    new_fill.set_foreground_color(color(color::type::auto_, fg_color_node.attribute("auto").as_ullong()));
-                }
-                else if(fg_color_node.attribute("theme") != nullptr)
-                {
-                    new_fill.set_foreground_color(color(color::type::theme, fg_color_node.attribute("theme").as_ullong()));
-                }
-            }
-        }
-
-        fills_.push_back(new_fill);
-    }
-}
-    
-void read_side(pugi::xml_node side_node, side &side, bool &assigned)
-{
-    
-    if(side_node != nullptr)
-    {
-        assigned = true;
-        
-        if(side_node.attribute("style") != nullptr)
-        {
-            std::string border_style_string = side_node.attribute("style").as_string();
-            
-            if(border_style_string == "none")
-            {
-                side.set_border_style(border_style::none);
-            }
-            else if(border_style_string == "dashdot")
-            {
-                side.set_border_style(border_style::dashdot);
-            }
-            else if(border_style_string == "dashdotdot")
-            {
-                side.set_border_style(border_style::dashdotdot);
-            }
-            else if(border_style_string == "dashed")
-            {
-                side.set_border_style(border_style::dashed);
-            }
-            else if(border_style_string == "dotted")
-            {
-                side.set_border_style(border_style::dotted);
-            }
-            else if(border_style_string == "double")
-            {
-                side.set_border_style(border_style::double_);
-            }
-            else if(border_style_string == "hair")
-            {
-                side.set_border_style(border_style::hair);
-            }
-            else if(border_style_string == "medium")
-            {
-                side.set_border_style(border_style::medium);
-            }
-            else if(border_style_string == "mediumdashdot")
-            {
-                side.set_border_style(border_style::mediumdashdot);
-            }
-            else if(border_style_string == "mediumdashdotdot")
-            {
-                side.set_border_style(border_style::mediumdashdotdot);
-            }
-            else if(border_style_string == "mediumdashed")
-            {
-                side.set_border_style(border_style::mediumdashed);
-            }
-            else if(border_style_string == "slantdashdot")
-            {
-                side.set_border_style(border_style::slantdashdot);
-            }
-            else if(border_style_string == "thick")
-            {
-                side.set_border_style(border_style::thick);
-            }
-            else if(border_style_string == "thin")
-            {
-                side.set_border_style(border_style::thin);
-            }
-            else
-            {
-                throw std::runtime_error("unknown border style");
-            }
-        }
-        
-        auto color_node = side_node.child("color");
-        
-        if(color_node != nullptr)
-        {
-            if(color_node.attribute("indexed") != nullptr)
-            {
-                side.set_color(side::color_type::indexed, color_node.attribute("indexed").as_int());
-            }
-            else if(color_node.attribute("theme") != nullptr)
-            {
-                side.set_color(side::color_type::theme, color_node.attribute("theme").as_int());
-            }
-            else
-            {
-                throw std::runtime_error("invalid color type");
-            }
-        }
-    }
-}
-
-void style_reader::read_borders(pugi::xml_node borders_node)
-{
-    for(auto border_node : borders_node)
-    {
-        border new_border;
-        
-        std::vector<std::tuple<std::string, side *, bool *>> sides;
-        sides.push_back(std::make_tuple("start", &new_border.start, &new_border.start_assigned));
-        sides.push_back(std::make_tuple("end", &new_border.end, &new_border.end_assigned));
-        sides.push_back(std::make_tuple("left", &new_border.left, &new_border.left_assigned));
-        sides.push_back(std::make_tuple("right", &new_border.right, &new_border.right_assigned));
-        sides.push_back(std::make_tuple("top", &new_border.top, &new_border.top_assigned));
-        sides.push_back(std::make_tuple("bottom", &new_border.bottom, &new_border.bottom_assigned));
-        sides.push_back(std::make_tuple("diagonal", &new_border.diagonal, &new_border.diagonal_assigned));
-        sides.push_back(std::make_tuple("vertical", &new_border.vertical, &new_border.vertical_assigned));
-        sides.push_back(std::make_tuple("horizontal", &new_border.horizontal, &new_border.horizontal_assigned));
-        
-        for(const auto &side : sides)
-        {
-            read_side(border_node.child(std::get<0>(side).c_str()), *std::get<1>(side), *std::get<2>(side));
-        }
-        
-        borders_.push_back(new_border);
-    }
-}
-
-void style_reader::read_named_styles(pugi::xml_node named_styles_node)
-{
-}
-    
-void style_reader::read_style_names()
-{
-}
-    
-void style_reader::read_cell_styles()
-{
-    
-}
-    
-void style_reader::read_xfs()
-{
-    
-}
-    
-void style_reader::read_style_table()
-{
-    
-}
-    
-} // namespace xlnt
\ No newline at end of file
diff --git a/source/reader/workbook_reader.cpp b/source/reader/workbook_reader.cpp
deleted file mode 100644
index 19158208..00000000
--- a/source/reader/workbook_reader.cpp
+++ /dev/null
@@ -1,240 +0,0 @@
-#include <algorithm>
-
-#include <xlnt/common/datetime.hpp>
-#include <xlnt/common/exceptions.hpp>
-#include <xlnt/common/zip_file.hpp>
-#include <xlnt/reader/workbook_reader.hpp>
-#include <xlnt/workbook/document_properties.hpp>
-#include <xlnt/workbook/workbook.hpp>
-
-#include "detail/include_pugixml.hpp"
-
-namespace {
-
-xlnt::datetime w3cdtf_to_datetime(const std::string &string)
-{
-    xlnt::datetime result(1900, 1, 1);
-    auto separator_index = string.find('-');
-    result.year = std::stoi(string.substr(0, separator_index));
-    result.month = std::stoi(string.substr(separator_index + 1, string.find('-', separator_index + 1)));
-    separator_index = string.find('-', separator_index + 1);
-    result.day = std::stoi(string.substr(separator_index + 1, string.find('T', separator_index + 1)));
-    separator_index = string.find('T', separator_index + 1);
-    result.hour = std::stoi(string.substr(separator_index + 1, string.find(':', separator_index + 1)));
-    separator_index = string.find(':', separator_index + 1);
-    result.minute = std::stoi(string.substr(separator_index + 1, string.find(':', separator_index + 1)));
-    separator_index = string.find(':', separator_index + 1);
-    result.second = std::stoi(string.substr(separator_index + 1, string.find('Z', separator_index + 1)));
-    return result;
-}
-    
-}
-
-namespace xlnt {
-
-std::vector<std::pair<std::string, std::string>> read_sheets(zip_file &archive)
-{
-    auto xml_source = archive.read("xl/workbook.xml");
-    pugi::xml_document doc;
-    doc.load(xml_source.c_str());
-    
-    std::string ns;
-    
-    for(auto child : doc.children())
-    {
-        std::string name = child.name();
-        
-        if(name.find(':') != std::string::npos)
-        {
-            auto colon_index = name.find(':');
-            ns = name.substr(0, colon_index);
-            break;
-        }
-    }
-    
-    auto with_ns = [&](const std::string &base) { return ns.empty() ? base : ns + ":" + base; };
-    
-    auto root_node = doc.child(with_ns("workbook").c_str());
-    auto sheets_node = root_node.child(with_ns("sheets").c_str());
-    
-    std::vector<std::pair<std::string, std::string>> sheets;
-    
-    // store temp because pugixml iteration uses the internal char array multiple times
-    auto sheet_element_name = with_ns("sheet");
-    
-    for(auto sheet_node : sheets_node.children(sheet_element_name.c_str()))
-    {
-        std::string id = sheet_node.attribute("r:id").as_string();
-        std::string name = sheet_node.attribute("name").as_string();
-        sheets.push_back(std::make_pair(id, name));
-    }
-    
-    return sheets;
-}
-
-document_properties read_properties_core(const std::string &xml_string)
-{
-    document_properties props;
-    pugi::xml_document doc;
-    doc.load(xml_string.c_str());
-    auto root_node = doc.child("cp:coreProperties");
-    
-    props.excel_base_date = calendar::windows_1900;
-    
-    if(root_node.child("dc:creator") != nullptr)
-    {
-        props.creator = root_node.child("dc:creator").text().as_string();
-    }
-    if(root_node.child("cp:lastModifiedBy") != nullptr)
-    {
-        props.last_modified_by = root_node.child("cp:lastModifiedBy").text().as_string();
-    }
-    if(root_node.child("dcterms:created") != nullptr)
-    {
-        std::string created_string = root_node.child("dcterms:created").text().as_string();
-        props.created = w3cdtf_to_datetime(created_string);
-    }
-    if(root_node.child("dcterms:modified") != nullptr)
-    {
-        std::string modified_string = root_node.child("dcterms:modified").text().as_string();
-        props.modified = w3cdtf_to_datetime(modified_string);
-    }
-    
-    return props;
-}
-
-std::string read_dimension(const std::string &xml_string)
-{
-    pugi::xml_document doc;
-    doc.load(xml_string.c_str());
-    auto root_node = doc.child("worksheet");
-    auto dimension_node = root_node.child("dimension");
-    std::string dimension = dimension_node.attribute("ref").as_string();
-    return dimension;
-}
-
-std::vector<relationship> read_relationships(zip_file &archive, const std::string &filename)
-{
-    auto filename_separator_index = filename.find_last_of('/');
-    auto basename = filename.substr(filename_separator_index + 1);
-    auto dirname = filename.substr(0, filename_separator_index);
-    auto rels_filename = dirname + "/_rels/" + basename + ".rels";
-    
-    pugi::xml_document doc;
-    auto content = archive.read(rels_filename);
-    doc.load(content.c_str());
-    
-    auto root_node = doc.child("Relationships");
-    
-    std::vector<relationship> relationships;
-    
-    for(auto relationship : root_node.children("Relationship"))
-    {
-        std::string id = relationship.attribute("Id").as_string();
-        std::string type = relationship.attribute("Type").as_string();
-        std::string target = relationship.attribute("Target").as_string();
-        
-        if(target[0] != '/' && target.substr(0, 2) != "..")
-        {
-            target = dirname + "/" + target;
-        }
-        
-        if(target[0] == '/')
-        {
-            target = target.substr(1);
-        }
-        
-        relationships.push_back(xlnt::relationship(type, id, target));
-    }
-    
-    return relationships;
-}
-
-std::vector<std::pair<std::string, std::string>> read_content_types(zip_file &archive)
-{
-    pugi::xml_document doc;
-    
-    try
-    {
-        auto content_types_string = archive.read("[Content_Types].xml");
-        doc.load(content_types_string.c_str());
-    }
-    catch(std::exception e)
-    {
-        throw invalid_file_exception(archive.get_filename());
-    }
-    
-    auto root_node = doc.child("Types");
-    
-    std::vector<std::pair<std::string, std::string>> override_types;
-    
-    for(auto child : root_node.children("Override"))
-    {
-        std::string part_name = child.attribute("PartName").as_string();
-        std::string content_type = child.attribute("ContentType").as_string();
-        override_types.push_back({part_name, content_type});
-    }
-    
-    return override_types;
-}
-
-std::string determine_document_type(const std::vector<std::pair<std::string, std::string>> &override_types)
-{
-    auto match = std::find_if(override_types.begin(), override_types.end(), [](const std::pair<std::string, std::string> &p) { return p.first == "/xl/workbook.xml"; });
-    
-    if(match == override_types.end())
-    {
-        return "unsupported";
-    }
-    
-    std::string type = match->second;
-    
-    if(type == "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml")
-    {
-        return "excel";
-    }
-    else if(type == "application/vnd.openxmlformats-officedocument.presentationml.presentation.main+xml")
-    {
-        return "powerpoint";
-    }
-    else if(type == "application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml")
-    {
-        return "word";
-    }
-    
-    return "unsupported";
-}
-
-std::vector<std::pair<std::string, std::string>> detect_worksheets(zip_file &archive)
-{
-    static const std::string ValidWorksheet = "application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml";
-    
-    auto content_types = read_content_types(archive);
-    std::vector<std::string> valid_sheets;
-    
-    for(const auto &content_type : content_types)
-    {
-        if(content_type.second == ValidWorksheet)
-        {
-            valid_sheets.push_back(content_type.first);
-        }
-    }
-    
-    auto workbook_relationships = read_relationships(archive, "xl/workbook.xml");
-    std::vector<std::pair<std::string, std::string>> result;
-    
-    for(const auto &ws : read_sheets(archive))
-    {
-        auto rel = *std::find_if(workbook_relationships.begin(), workbook_relationships.end(), [&](const relationship &r) { return r.get_id() == ws.first; });
-        auto target = rel.get_target_uri();
-        
-        if(std::find(valid_sheets.begin(), valid_sheets.end(), "/" + target) != valid_sheets.end())
-        {
-            result.push_back({target, ws.second});
-        }
-    }
-    
-    return result;
-}
-
-}
diff --git a/source/s11n/comment_serializer.cpp b/source/s11n/comment_serializer.cpp
new file mode 100644
index 00000000..3b0230c1
--- /dev/null
+++ b/source/s11n/comment_serializer.cpp
@@ -0,0 +1,5 @@
+#include <xlnt/s11n/comment_serializer.hpp>
+
+namespace {
+    
+} // namespace xlnt
diff --git a/source/reader/excel_reader.cpp b/source/s11n/excel_serializer.cpp
similarity index 58%
rename from source/reader/excel_reader.cpp
rename to source/s11n/excel_serializer.cpp
index 048b2ef5..ada9b873 100644
--- a/source/reader/excel_reader.cpp
+++ b/source/s11n/excel_serializer.cpp
@@ -1,17 +1,7 @@
-#include <xlnt/common/datetime.hpp>
-#include <xlnt/common/exceptions.hpp>
-#include <xlnt/common/zip_file.hpp>
-#include <xlnt/styles/style.hpp>
-#include <xlnt/reader/excel_reader.hpp>
-#include <xlnt/reader/shared_strings_reader.hpp>
-#include <xlnt/reader/style_reader.hpp>
-#include <xlnt/reader/workbook_reader.hpp>
-#include <xlnt/reader/worksheet_reader.hpp>
-#include <xlnt/workbook/document_properties.hpp>
+#include <xlnt/s11n/excel_serializer.hpp>
+#include <xlnt/s11n/manifest_serializer.hpp>
+#include <xlnt/workbook/manifest.hpp>
 #include <xlnt/workbook/workbook.hpp>
-#include <xlnt/worksheet/worksheet.hpp>
-
-#include "detail/include_pugixml.hpp"
 
 namespace {
     
@@ -166,4 +156,112 @@ xlnt::workbook excel_reader::load_workbook(const std::vector<std::uint8_t> &byte
     return ::load_workbook(archive, guess_types, data_only);
 }
     
+excel_writer::excel_writer(workbook &wb) : wb_(wb)
+{
+}
+
+void excel_writer::save(const std::string &filename, bool as_template)
+{
+    zip_file archive;
+    write_data(archive, as_template);
+    archive.save(filename);
+}
+
+void excel_writer::write_data(zip_file &archive, bool as_template)
+{
+    archive.writestr(constants::ArcRootRels, write_root_rels(wb_));
+    archive.writestr(constants::ArcWorkbookRels, write_workbook_rels(wb_));
+    archive.writestr(constants::ArcApp, write_properties_app(wb_));
+    archive.writestr(constants::ArcCore, write_properties_core(wb_.get_properties()));
+    
+    if(wb_.has_loaded_theme())
+    {
+        archive.writestr(constants::ArcTheme, wb_.get_loaded_theme());
+    }
+    else
+    {
+        archive.writestr(constants::ArcTheme, write_theme());
+    }
+    
+    archive.writestr(constants::ArcWorkbook, write_workbook(wb_));
+    
+    auto shared_strings = extract_all_strings(wb_);
+    
+    write_charts(archive);
+    write_images(archive);
+    write_shared_strings(archive, shared_strings);
+    write_worksheets(archive, shared_strings);
+    write_chartsheets(archive);
+    write_external_links(archive);
+    
+    style_writer style_writer_(wb_);
+    archive.writestr(constants::ArcStyles, style_writer_.write_table());
+    
+    auto manifest = write_content_types(wb_, as_template);
+    archive.writestr(constants::ArcContentTypes, manifest);
+}
+
+void excel_writer::write_shared_strings(xlnt::zip_file &archive, const std::vector<std::string> &shared_strings)
+{
+    archive.writestr(constants::ArcSharedString, ::xlnt::write_shared_strings(shared_strings));
+}
+
+void excel_writer::write_images(zip_file &/*archive*/)
+{
+    
+}
+
+void excel_writer::write_charts(zip_file &/*archive*/)
+{
+    
+}
+
+void excel_writer::write_chartsheets(zip_file &/*archive*/)
+{
+    
+}
+
+void excel_writer::write_worksheets(zip_file &archive, const std::vector<std::string> &shared_strings)
+{
+    std::size_t index = 0;
+    
+    for(auto ws : wb_)
+    {
+        for(auto relationship : wb_.get_relationships())
+        {
+            if(relationship.get_type() == relationship::type::worksheet &&
+               workbook::index_from_ws_filename(relationship.get_target_uri()) == index)
+            {
+                archive.writestr(relationship.get_target_uri(), write_worksheet(ws, shared_strings));
+                break;
+            }
+        }
+        
+        index++;
+    }
+}
+
+void excel_writer::write_external_links(zip_file &/*archive*/)
+{
+    
+}
+
+bool save_workbook(workbook &wb, const std::string &filename, bool as_template)
+{
+    excel_writer writer(wb);
+    writer.save(filename, as_template);
+    return true;
+}
+
+std::vector<std::uint8_t> save_virtual_workbook(xlnt::workbook &wb, bool as_template)
+{
+    zip_file archive;
+    excel_writer writer(wb);
+    writer.write_data(archive, as_template);
+    std::vector<std::uint8_t> buffer;
+    archive.save(buffer);
+    
+    return buffer;
+}
+    
 } // namespace xlnt
diff --git a/source/s11n/manifest_serializer.cpp b/source/s11n/manifest_serializer.cpp
new file mode 100644
index 00000000..6650e6ec
--- /dev/null
+++ b/source/s11n/manifest_serializer.cpp
@@ -0,0 +1,33 @@
+#include <xlnt/s11n/manifest_serializer.hpp>
+#include <xlnt/s11n/xml_document.hpp>
+#include <xlnt/workbook/manifest.hpp>
+
+#include "detail/constants.hpp"
+
+namespace xlnt {
+
+bool manifest_serializer::write_manifest(xml_document &xml)
+{
+    xml.add_namespace("", constants::Namespaces.at("content-types"));
+    
+    auto root_node = xml.root();
+    root_node.set_name("Types");
+    
+    for(const auto &default_type : manifest_.get_default_types())
+    {
+        auto type_node = root_node.add_child("Default");
+        type_node.add_attribute("Extension", default_type.get_extension());
+        type_node.add_attribute("ContentType", default_type.get_extension());
+    }
+    
+    for(const auto &override_type : manifest_.get_override_types())
+    {
+        auto type_node = root_node.add_child("Override");
+        type_node.add_attribute("PartName", override_type.get_part_name());
+        type_node.add_attribute("ContentType", override_type.get_content_type());
+    }
+    
+    return true;
+}
+
+} // namespace xlnt
diff --git a/source/s11n/relationship_serializer.cpp b/source/s11n/relationship_serializer.cpp
new file mode 100644
index 00000000..28ea0080
--- /dev/null
+++ b/source/s11n/relationship_serializer.cpp
@@ -0,0 +1,47 @@
+#include <xlnt/s11n/relationship_serializer.hpp>
+
+#include <xlnt/common/relationship.hpp>
+#include <xlnt/s11n/xml_document.hpp>
+#include <xlnt/s11n/xml_node.hpp>
+
+#include "detail/constants.hpp"
+
+namespace xlnt {
+
+bool relationship_serializer::read_relationships(const xml_document &xml, const std::string &dir, std::vector<relationship> &relationships)
+{
+    return false;
+}
+    
+bool relationship_serializer::write_relationships(const std::vector<relationship> &relationships, const std::string &dir, xml_document &xml)
+{
+    xml.add_namespace("", constants::Namespaces.at("relationships"));
+    
+    auto root_node = xml.root();
+    root_node.set_name("Relationships");
+    
+    for(const auto &relationship : relationships)
+    {
+        auto target = relationship.get_target_uri();
+        
+        if (dir != "" && target.substr(0, dir.size()) == dir)
+        {
+            target = target.substr(dir.size());
+        }
+        
+        auto app_props_node = root_node.add_child("Relationship");
+        
+        app_props_node.add_attribute("Id", relationship.get_id());
+        app_props_node.add_attribute("Target", target);
+        app_props_node.add_attribute("Type", relationship.get_type_string());
+        
+        if(relationship.get_target_mode() == target_mode::external)
+        {
+            app_props_node.add_attribute("TargetMode", "External");
+        }
+    }
+
+    return true;
+}
+    
+}
diff --git a/source/s11n/shared_strings_serializer.cpp b/source/s11n/shared_strings_serializer.cpp
new file mode 100644
index 00000000..d469f049
--- /dev/null
+++ b/source/s11n/shared_strings_serializer.cpp
@@ -0,0 +1,29 @@
+#include <xlnt/s11n/shared_strings_serializer.hpp>
+#include <xlnt/s11n/xml_document.hpp>
+#include <xlnt/s11n/xml_node.hpp>
+
+namespace xlnt {
+
+bool shared_strings_serializer::read_strings(const xml_document &xml, std::vector<std::string> &strings)
+{
+    strings.clear();
+    
+    auto root_node = xml.root();
+    root_node.set_name("sst");
+    
+    auto unique_count = std::stoull(root_node.get_attribute("uniqueCount"));
+    
+    for(const auto &si_node : root_node.get_children())
+    {
+        strings.push_back(si_node.get_child("t").get_text());
+    }
+    
+    if(unique_count != strings.size())
+    {
+        throw std::runtime_error("counts don't match");
+    }
+    
+    return true;
+}
+
+} // namespace xlnt
diff --git a/source/s11n/style_serializer.cpp b/source/s11n/style_serializer.cpp
new file mode 100644
index 00000000..f219bf39
--- /dev/null
+++ b/source/s11n/style_serializer.cpp
@@ -0,0 +1,900 @@
+#include <xlnt/s11n/style_serializer.hpp>
+#include <xlnt/s11n/xml_document.hpp>
+#include <xlnt/s11n/xml_node.hpp>
+#include <xlnt/styles/alignment.hpp>
+#include <xlnt/styles/border.hpp>
+#include <xlnt/styles/fill.hpp>
+#include <xlnt/styles/font.hpp>
+#include <xlnt/styles/number_format.hpp>
+#include <xlnt/styles/protection.hpp>
+#include <xlnt/styles/style.hpp>
+
+namespace {
+
+bool is_true(const std::string &bool_string)
+{
+    return bool_string == "1";
+}
+
+xlnt::protection::type protection_type_from_string(const std::string &type_string)
+{
+    if(type_string == "true")
+    {
+        return xlnt::protection::type::protected_;
+    }
+    else if(type_string == "inherit")
+    {
+        return xlnt::protection::type::inherit;
+    }
+    
+    return xlnt::protection::type::unprotected;
+};
+
+xlnt::font::underline_style underline_style_from_string(const std::string &underline_string)
+{
+    if(underline_string == "none")
+    {
+        return xlnt::font::underline_style::none;
+    }
+    else if(underline_string == "single")
+    {
+        return xlnt::font::underline_style::single;
+    }
+    else if(underline_string == "single-accounting")
+    {
+        return xlnt::font::underline_style::single_accounting;
+    }
+    else if(underline_string == "double")
+    {
+        return xlnt::font::underline_style::double_;
+    }
+    else if(underline_string == "double-accounting")
+    {
+        return xlnt::font::underline_style::double_accounting;
+    }
+    
+    return xlnt::font::underline_style::none;
+}
+    
+xlnt::fill::pattern_type pattern_fill_type_from_string(const std::string &fill_type)
+{
+    if(fill_type == "none") return xlnt::fill::pattern_type::none;
+    if(fill_type == "solid") return xlnt::fill::pattern_type::solid;
+    if(fill_type == "gray125") return xlnt::fill::pattern_type::gray125;
+    return xlnt::fill::pattern_type::none;
+};
+
+xlnt::border_style border_style_from_string(const std::string &border_style_string)
+{
+    if(border_style_string == "none")
+    {
+        return xlnt::border_style::none;
+    }
+    else if(border_style_string == "dashdot")
+    {
+        return xlnt::border_style::dashdot;
+    }
+    else if(border_style_string == "dashdotdot")
+    {
+        return xlnt::border_style::dashdotdot;
+    }
+    else if(border_style_string == "dashed")
+    {
+        return xlnt::border_style::dashed;
+    }
+    else if(border_style_string == "dotted")
+    {
+        return xlnt::border_style::dotted;
+    }
+    else if(border_style_string == "double")
+    {
+        return xlnt::border_style::double_;
+    }
+    else if(border_style_string == "hair")
+    {
+        return xlnt::border_style::hair;
+    }
+    else if(border_style_string == "medium")
+    {
+        return xlnt::border_style::medium;
+    }
+    else if(border_style_string == "mediumdashdot")
+    {
+        return xlnt::border_style::mediumdashdot;
+    }
+    else if(border_style_string == "mediumdashdotdot")
+    {
+        return xlnt::border_style::mediumdashdotdot;
+    }
+    else if(border_style_string == "mediumdashed")
+    {
+        return xlnt::border_style::mediumdashed;
+    }
+    else if(border_style_string == "slantdashdot")
+    {
+        return xlnt::border_style::slantdashdot;
+    }
+    else if(border_style_string == "thick")
+    {
+        return xlnt::border_style::thick;
+    }
+    else if(border_style_string == "thin")
+    {
+        return xlnt::border_style::thin;
+    }
+    else
+    {
+        throw std::runtime_error("unknown border style");
+    }
+}
+    
+} // namespace
+
+namespace xlnt {    
+
+style_serializer::style_serializer(workbook &wb) : wb_(wb)
+{
+}
+    
+protection style_serializer::read_protection(const xml_node &protection_node) const
+{
+    protection prot;
+    
+    prot.set_locked(protection_type_from_string(protection_node.get_attribute("locked")));
+    prot.set_hidden(protection_type_from_string(protection_node.get_attribute("hidden")));
+    
+    return prot;
+}
+
+alignment style_serializer::read_alignment(const xml_node &alignment_node) const
+{
+    alignment align;
+    
+    align.set_wrap_text(is_true(alignment_node.get_attribute("wrapText")));
+    
+    bool has_vertical = alignment_node.has_attribute("vertical");
+    
+    if(has_vertical)
+    {
+        std::string vertical = alignment_node.get_attribute("vertical");
+        
+        if(vertical == "bottom")
+        {
+            align.set_vertical(alignment::vertical_alignment::bottom);
+        }
+        else if(vertical =="center")
+        {
+            align.set_vertical(alignment::vertical_alignment::center);
+        }
+        else if(vertical =="justify")
+        {
+            align.set_vertical(alignment::vertical_alignment::justify);
+        }
+        else if(vertical =="top")
+        {
+            align.set_vertical(alignment::vertical_alignment::top);
+        }
+        else
+        {
+            throw "unknown alignment";
+        }
+    }
+    
+    bool has_horizontal = alignment_node.has_attribute("horizontal");
+    
+    if(has_horizontal)
+    {
+        std::string horizontal = alignment_node.get_attribute("horizontal");
+        
+        if(horizontal == "left")
+        {
+            align.set_horizontal(alignment::horizontal_alignment::left);
+        }
+        else if(horizontal == "center")
+        {
+            align.set_horizontal(alignment::horizontal_alignment::center);
+        }
+        else if(horizontal == "center-continuous")
+        {
+            align.set_horizontal(alignment::horizontal_alignment::center_continuous);
+        }
+        else if(horizontal == "right")
+        {
+            align.set_horizontal(alignment::horizontal_alignment::right);
+        }
+        else if(horizontal == "justify")
+        {
+            align.set_horizontal(alignment::horizontal_alignment::justify);
+        }
+        else if(horizontal == "general")
+        {
+            align.set_horizontal(alignment::horizontal_alignment::general);
+        }
+        else
+        {
+            throw "unknown alignment";
+        }
+    }
+    
+    return align;
+}
+
+style style_serializer::read_style(const xml_node &style_node) const
+{
+    style s;
+    
+    s.apply_number_format(is_true(style_node.get_attribute("applyNumberFormat")));
+    s.number_format_id_ = std::stoull(style_node.get_attribute("numFmtId"));
+    
+    bool builtin_format = true;
+    
+    for(auto num_fmt : wb_.get_number_formats())
+    {
+        if(num_fmt.get_id() == s.get_number_format_id())
+        {
+            s.number_format_ = num_fmt;
+            builtin_format = false;
+            break;
+        }
+    }
+    
+    if(builtin_format)
+    {
+        s.number_format_ = number_format::from_builtin_id(s.get_number_format_id());
+    }
+    
+    s.apply_font(is_true(style_node.get_attribute("applyFont")));
+    s.font_id_ = style_node.has_attribute("fontId") ? std::stoull(style_node.get_attribute("fontId")) : 0;
+    s.font_ = wb_.get_font(s.font_id_);
+    
+    s.apply_fill(is_true(style_node.get_attribute("applyFill")));
+    s.fill_id_ = style_node.has_attribute("fillId") ? std::stoull(style_node.get_attribute("fillId")) : 0;
+    s.fill_ = wb_.get_fill(s.fill_id_);
+    
+    s.apply_border(is_true(style_node.get_attribute("applyBorder")));
+    s.border_id_ = style_node.has_attribute("borderId") ? std::stoull(style_node.get_attribute("borderId")) : 0;
+    s.border_ = wb_.get_border(s.border_id_);
+    
+    s.apply_protection(style_node.has_attribute("protection"));
+    
+    if(s.protection_apply_)
+    {
+        auto inline_protection = read_protection(style_node.get_child("protection"));
+        s.protection_ = inline_protection;
+    }
+    
+    s.apply_alignment(style_node.has_child("alignment"));
+    
+    if(s.alignment_apply_)
+    {
+        auto inline_alignment = read_alignment(style_node.get_child("alignment"));
+        s.alignment_ = inline_alignment;
+    }
+    
+    return s;
+}
+
+bool style_serializer::read_stylesheet(const xml_document &xml)
+{
+    auto stylesheet_node = xml.root();
+    
+    read_borders(stylesheet_node.get_child("borders"));
+    read_fills(stylesheet_node.get_child("fills"));
+    read_fonts(stylesheet_node.get_child("fonts"));
+    read_number_formats(stylesheet_node.get_child("numFmts"));
+    read_colors(stylesheet_node.get_child("colors"));
+    
+    auto cell_xfs_node = stylesheet_node.get_child("cellXfs");
+    
+    for(auto xf_node : cell_xfs_node.get_children())
+    {
+        if(xf_node.get_name() != "xf")
+        {
+            continue;
+        }
+        
+        wb_.add_style(read_style(xf_node));
+    }
+    
+    return true;
+}
+
+bool style_serializer::read_number_formats(const xml_node &number_formats_node)
+{
+    for(auto num_fmt_node : number_formats_node.get_children())
+    {
+        if(num_fmt_node.get_name() != "numFmt")
+        {
+            continue;
+        }
+        
+        auto format_string = num_fmt_node.get_attribute("formatCode");
+        
+        if(format_string == "GENERAL")
+        {
+            format_string = "General";
+        }
+        
+        number_format nf;
+        
+        nf.set_format_string(format_string);
+        nf.set_id(std::stoull(num_fmt_node.get_attribute("numFmtId")));
+        
+        wb_.add_number_format(nf);
+    }
+    
+    return true;
+}
+
+bool style_serializer::read_fonts(const xml_node &fonts_node)
+{
+    for(auto font_node : fonts_node.get_children())
+    {
+        wb_.add_font(read_font(font_node));
+    }
+    
+    return true;
+}
+    
+font style_serializer::read_font(const xlnt::xml_node &font_node) const
+{
+    font new_font;
+    
+    new_font.set_size(std::stoi(font_node.get_child("sz").get_attribute("val")));
+    new_font.set_name(font_node.get_child("name").get_attribute("val"));
+    
+    if(font_node.has_child("color"))
+    {
+        new_font.set_color(read_color(font_node.get_child("color")));
+    }
+    
+    if(font_node.has_child("family"))
+    {
+        new_font.set_family(std::stoull(font_node.get_child("family").get_attribute("val")));
+    }
+    
+    if(font_node.has_child("scheme"))
+    {
+        new_font.set_scheme(font_node.get_child("scheme").get_attribute("val"));
+    }
+    
+    if(font_node.has_child("b"))
+    {
+        new_font.set_bold(is_true(font_node.get_child("b").get_attribute("val")));
+    }
+    
+    if(font_node.has_child("strike"))
+    {
+        new_font.set_strikethrough(is_true(font_node.get_child("strike").get_attribute("val")));
+    }
+    
+    if(font_node.has_child("i"))
+    {
+        new_font.set_italic(is_true(font_node.get_child("i").get_attribute("val")));
+    }
+    
+    if(font_node.has_child("u"))
+    {
+        std::string underline_string = font_node.get_child("u").get_attribute("val");
+        new_font.set_underline(underline_style_from_string(underline_string));
+    }
+    
+    return new_font;
+}
+
+bool style_serializer::read_colors(const xml_node &colors_node)
+{
+    if(colors_node.has_child("indexedColors"))
+    {
+        auto indexed_colors = read_indexed_colors(colors_node.get_child("indexedColors"));
+        
+        for(const auto &indexed_color : indexed_colors)
+        {
+            wb_.add_color(indexed_color);
+        }
+    }
+    
+    return true;
+}
+
+bool style_serializer::read_fills(const xml_node &fills_node)
+{
+    for(auto fill_node : fills_node.get_children())
+    {
+        wb_.add_fill(read_fill(fill_node));
+    }
+    
+    return true;
+}
+
+fill style_serializer::read_fill(const xml_node &fill_node) const
+{
+    fill new_fill;
+    
+    if(fill_node.has_child("patternFill"))
+    {
+        new_fill.set_type(fill::type::pattern);
+        
+        auto pattern_fill_node = fill_node.get_child("patternFill");
+        new_fill.set_pattern_type(pattern_fill_type_from_string(pattern_fill_node.get_attribute("patternType")));
+        
+        if(pattern_fill_node.has_child("bgColor"))
+        {
+            new_fill.set_background_color(read_color(pattern_fill_node.get_child("bgColor")));
+        }
+        
+        if(pattern_fill_node.has_child("fgColor"))
+        {
+            new_fill.set_foreground_color(read_color(pattern_fill_node.get_child("fgColor")));
+        }
+    }
+    
+    return new_fill;
+}
+
+side style_serializer::read_side(const xml_node &side_node) const
+{
+    side new_side;
+    
+    if(side_node.has_attribute("style"))
+    {
+        new_side.set_border_style(border_style_from_string(side_node.get_attribute("style")));
+    }
+    
+    if(side_node.has_child("color"))
+    {
+        new_side.set_color(read_color(side_node.get_child("color")));
+    }
+    
+    return new_side;
+}
+
+bool style_serializer::read_borders(const xml_node &borders_node)
+{
+    for(auto border_node : borders_node.get_children())
+    {
+        wb_.add_border(read_border(border_node));
+    }
+    
+    return true;
+}
+
+border style_serializer::read_border(const xml_node &border_node) const
+{
+    border new_border;
+    
+    if(border_node.has_child("start"))
+    {
+        new_border.start_assigned = true;
+        new_border.start = read_side(border_node.get_child("start"));
+    }
+    
+    if(border_node.has_child("end"))
+    {
+        new_border.end_assigned = true;
+        new_border.end = read_side(border_node.get_child("end"));
+    }
+    
+    if(border_node.has_child("left"))
+    {
+        new_border.left_assigned = true;
+        new_border.left = read_side(border_node.get_child("left"));
+    }
+    
+    if(border_node.has_child("right"))
+    {
+        new_border.right_assigned = true;
+        new_border.right = read_side(border_node.get_child("right"));
+    }
+    
+    if(border_node.has_child("top"))
+    {
+        new_border.top_assigned = true;
+        new_border.top = read_side(border_node.get_child("top"));
+    }
+    
+    if(border_node.has_child("bottom"))
+    {
+        new_border.bottom_assigned = true;
+        new_border.bottom = read_side(border_node.get_child("bottom"));
+    }
+    
+    if(border_node.has_child("diagonal"))
+    {
+        new_border.diagonal_assigned = true;
+        new_border.diagonal = read_side(border_node.get_child("diagonal"));
+    }
+    
+    if(border_node.has_child("vertical"))
+    {
+        new_border.vertical_assigned = true;
+        new_border.vertical = read_side(border_node.get_child("vertical"));
+    }
+    
+    if(border_node.has_child("horizontal"))
+    {
+        new_border.horizontal_assigned = true;
+        new_border.horizontal = read_side(border_node.get_child("horizontal"));
+    }
+    
+    return new_border;
+}
+
+bool style_serializer::write_stylesheet(xlnt::xml_document &xml) const
+{
+    xml.add_namespace("", "http://schemas.openxmlformats.org/spreadsheetml/2006/main");
+    xml.add_namespace("mc", "http://schemas.openxmlformats.org/markup-compatibility/2006");
+    xml.add_namespace("x14ac", "http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac");
+    
+    auto &style_sheet_node = doc.add_child("styleSheet");
+    xml.add_attribute("mc:Ignorable", "x14ac");
+    
+    auto num_fmts_node = style_sheet_node.add_child("numFmts");
+    auto num_fmts = wb_.get_number_formats();
+    num_fmts_node.add_attribute("count", static_cast<int>(num_fmts.size()));
+    
+    for(auto &num_fmt : num_fmts)
+    {
+        auto num_fmt_node = num_fmts_node.add_child("numFmt");
+        num_fmt_node.add_attribute("numFmtId", num_fmt.get_id());
+        num_fmt_node.add_attribute("formatCode", num_fmt.get_format_string());
+    }
+
+    auto fonts_node = style_sheet_node.add_child("fonts");
+    auto fonts = wb_.get_fonts();
+    if(fonts.empty())
+    {
+        fonts.push_back(font());
+    }
+    fonts_node.add_attribute("count", static_cast<int>(fonts.size()));
+    fonts_node.add_attribute("x14ac:knownFonts", 1);
+    
+    for(auto &f : fonts)
+    {
+        auto font_node = fonts_node.add_child("font");
+        
+        if(f.is_bold())
+        {
+            auto bold_node = font_node.add_child("b");
+            bold_node.add_attribute("val", 1);
+        }
+        
+        if(f.is_italic())
+        {
+            auto bold_node = font_node.add_child("i");
+            bold_node.add_attribute("val", 1);
+        }
+        
+        if(f.is_underline())
+        {
+            auto bold_node = font_node.add_child("u");
+            
+            switch(f.get_underline())
+            {
+                case font::underline_style::single:
+                    bold_node.add_attribute("val", "single");
+                    break;
+                default:
+                    break;
+            }
+        }
+        
+        if(f.is_strikethrough())
+        {
+            auto bold_node = font_node.add_child("strike");
+            bold_node.add_attribute("val", 1);
+        }
+        
+        auto size_node = font_node.add_child("sz");
+        size_node.add_attribute("val", f.get_size());
+        
+        auto color_node = font_node.add_child("color");
+        
+        if(f.get_color().get_type() == color::type::indexed)
+        {
+            color_node.add_attribute("indexed", static_cast<unsigned int>(f.get_color().get_index()));
+        }
+        else if(f.get_color().get_type() == color::type::theme)
+        {
+            color_node.add_attribute("theme", static_cast<unsigned int>(f.get_color().get_theme()));
+        }
+        
+        auto name_node = font_node.add_child("name");
+        name_node.add_attribute("val", f.get_name());
+        
+        if(f.has_family())
+        {
+            auto family_node = font_node.add_child("family");
+            family_node.add_attribute("val", 2);
+        }
+        
+        if(f.has_scheme())
+        {
+            auto scheme_node = font_node.add_child("scheme");
+            scheme_node.add_attribute("val", "minor");
+        }
+    }
+
+    auto fills_node = style_sheet_node.add_child("fills");
+    const auto &fills = wb_.get_fills();
+    fills_node.add_attribute("count", static_cast<unsigned int>(fills.size()));
+    
+    for(auto &fill_ : fills)
+    {
+        auto fill_node = fills_node.add_child("fill");
+        
+        if(fill_.get_type() == fill::type::pattern)
+        {
+            auto pattern_fill_node = fill_node.add_child("patternFill");
+            auto type_string = fill_.get_pattern_type_string();
+            pattern_fill_node.add_attribute("patternType", type_string);
+            
+            if(fill_.has_foreground_color())
+            {
+                auto fg_color_node = pattern_fill_node.add_child("fgColor");
+                
+                switch(fill_.get_foreground_color().get_type())
+                {
+                    case color::type::auto_: fg_color_node.add_attribute("auto", fill_.get_foreground_color().get_auto()); break;
+                    case color::type::theme: fg_color_node.add_attribute("theme", fill_.get_foreground_color().get_theme()); break;
+                    case color::type::indexed: fg_color_node.add_attribute("indexed", fill_.get_foreground_color().get_index()); break;
+                    default: throw std::runtime_error("bad type");
+                }
+            }
+            
+            if(fill_.has_background_color())
+            {
+                auto bg_color_node = pattern_fill_node.add_child("bgColor");
+                
+                switch(fill_.get_background_color().get_type())
+                {
+                    case color::type::auto_: bg_color_node.add_attribute("auto", fill_.get_background_color().get_auto()); break;
+                    case color::type::theme: bg_color_node.add_attribute("theme", fill_.get_background_color().get_theme()); break;
+                    case color::type::indexed: bg_color_node.add_attribute("indexed", fill_.get_background_color().get_index()); break;
+                    default: throw std::runtime_error("bad type");
+                }
+            }
+        }
+        else if(fill_.get_type() == fill::type::solid)
+        {
+            auto solid_fill_node = fill_node.add_child("solidFill");
+            solid_fill_node.add_child("color");
+        }
+        else if(fill_.get_type() == fill::type::gradient)
+        {
+            auto gradient_fill_node = fill_node.add_child("gradientFill");
+            
+            if(fill_.get_gradient_type_string() == "linear")
+            {
+                gradient_fill_node.add_attribute("degree", fill_.get_rotation());
+            }
+            else if(fill_.get_gradient_type_string() == "path")
+            {
+                gradient_fill_node.add_attribute("left", fill_.get_gradient_left());
+                gradient_fill_node.add_attribute("right", fill_.get_gradient_right());
+                gradient_fill_node.add_attribute("top", fill_.get_gradient_top());
+                gradient_fill_node.add_attribute("bottom", fill_.get_gradient_bottom());
+                
+                auto start_node = gradient_fill_node.add_child("stop");
+                start_node.add_attribute("position", 0);
+                
+                auto end_node = gradient_fill_node.add_child("stop");
+                end_node.add_attribute("position", 1);
+            }
+        }
+    }
+
+    auto borders_node = style_sheet_node.add_child("borders");
+    const auto &borders = wb_.get_borders();
+    borders_node.add_attribute("count", static_cast<unsigned int>(borders.size()));
+    
+    for(const auto &border_ : borders)
+    {
+        auto border_node = borders_node.add_child("border");
+        
+        std::vector<std::tuple<std::string, const side, bool>> sides;
+        sides.push_back(std::make_tuple("start", border_.start, border_.start_assigned));
+        sides.push_back(std::make_tuple("end", border_.end, border_.end_assigned));
+        sides.push_back(std::make_tuple("left", border_.left, border_.left_assigned));
+        sides.push_back(std::make_tuple("right", border_.right, border_.right_assigned));
+        sides.push_back(std::make_tuple("top", border_.top, border_.top_assigned));
+        sides.push_back(std::make_tuple("bottom", border_.bottom, border_.bottom_assigned));
+        sides.push_back(std::make_tuple("diagonal", border_.diagonal, border_.diagonal_assigned));
+        sides.push_back(std::make_tuple("vertical", border_.vertical, border_.vertical_assigned));
+        sides.push_back(std::make_tuple("horizontal", border_.horizontal, border_.horizontal_assigned));
+        
+        for(const auto &side_tuple : sides)
+        {
+            std::string name = std::get<0>(side_tuple);
+            const side side_ = std::get<1>(side_tuple);
+            bool assigned = std::get<2>(side_tuple);
+            
+            if(assigned)
+            {
+                auto side_node = border_node.add_child(name);
+                
+                if(side_.is_style_assigned())
+                {
+                    auto style_attribute = side_node.add_attribute("style");
+                    
+                    switch(side_.get_style())
+                    {
+                        case border_style::none: style_attribute.set_value("none"); break;
+                        case border_style::dashdot : style_attribute.set_value("dashdot"); break;
+                        case border_style::dashdotdot : style_attribute.set_value("dashdotdot"); break;
+                        case border_style::dashed : style_attribute.set_value("dashed"); break;
+                        case border_style::dotted : style_attribute.set_value("dotted"); break;
+                        case border_style::double_ : style_attribute.set_value("double"); break;
+                        case border_style::hair : style_attribute.set_value("hair"); break;
+                        case border_style::medium : style_attribute.set_value("thin"); break;
+                        case border_style::mediumdashdot: style_attribute.set_value("mediumdashdot"); break;
+                        case border_style::mediumdashdotdot: style_attribute.set_value("mediumdashdotdot"); break;
+                        case border_style::mediumdashed: style_attribute.set_value("mediumdashed"); break;
+                        case border_style::slantdashdot: style_attribute.set_value("slantdashdot"); break;
+                        case border_style::thick: style_attribute.set_value("thick"); break;
+                        case border_style::thin: style_attribute.set_value("thin"); break;
+                        default: throw std::runtime_error("invalid style");
+                    }
+                }
+                
+                if(side_.is_color_assigned())
+                {
+                    auto color_node = side_node.add_child("color");
+                    
+                    if(side_.get_color_type() == side::color_type::indexed)
+                    {
+                        color_node.add_attribute("indexed", (int)side_.get_color());
+                    }
+                    else if(side_.get_color_type() == side::color_type::theme)
+                    {
+                        color_node.add_attribute("indexed", (int)side_.get_color());
+                    }
+                    else
+                    {
+                        throw std::runtime_error("invalid color type");
+                    }
+                }
+            }
+        }
+    }
+
+    auto cell_style_xfs_node = style_sheet_node.add_child("cellStyleXfs");
+    cell_style_xfs_node.add_attribute("count", 1);
+    auto style_xf_node = cell_style_xfs_node.add_child("xf");
+    style_xf_node.add_attribute("numFmtId", 0);
+    style_xf_node.add_attribute("fontId", 0);
+    style_xf_node.add_attribute("fillId", 0);
+    style_xf_node.add_attribute("borderId", 0);
+    
+    auto cell_xfs_node = style_sheet_node.add_child("cellXfs");
+    const auto &styles = wb_.get_styles();
+    cell_xfs_node.add_attribute("count", static_cast<int>(styles.size()));
+    
+    for(auto &style : styles)
+    {
+        auto xf_node = cell_xfs_node.add_child("xf");
+        xf_node.add_attribute("numFmtId", style.get_number_format().get_id());
+        xf_node.add_attribute("fontId", (int)style.get_font_id());
+        
+        if(style.fill_apply_)
+        {
+            xf_node.add_attribute("fillId", (int)style.get_fill_id());
+        }
+        
+        if(style.border_apply_)
+        {
+            xf_node.add_attribute("borderId", (int)style.get_border_id());
+        }
+        
+        xf_node.add_attribute("applyNumberFormat", style.number_format_apply_ ? 1 : 0);
+        xf_node.add_attribute("applyFont", style.font_apply_ ? 1 : 0);
+        xf_node.add_attribute("applyFill", style.fill_apply_ ? 1 : 0);
+        xf_node.add_attribute("applyBorder", style.border_apply_ ? 1 : 0);
+        xf_node.add_attribute("applyAlignment", style.alignment_apply_ ? 1 : 0);
+        xf_node.add_attribute("applyProtection", style.protection_apply_ ? 1 : 0);
+        
+        if(style.alignment_apply_)
+        {
+            auto alignment_node = xf_node.add_child("alignment");
+            
+            if(style.alignment_.has_vertical())
+            {
+                switch(style.alignment_.get_vertical())
+                {
+                    case alignment::vertical_alignment::bottom:
+                        alignment_node.add_attribute("vertical", "bottom");
+                        break;
+                    case alignment::vertical_alignment::center:
+                        alignment_node.add_attribute("vertical", "center");
+                        break;
+                    case alignment::vertical_alignment::justify:
+                        alignment_node.add_attribute("vertical", "justify");
+                        break;
+                    case alignment::vertical_alignment::top:
+                        alignment_node.add_attribute("vertical", "top");
+                        break;
+                    default:
+                        throw std::runtime_error("invalid alignment");
+                }
+            }
+            
+            if(style.alignment_.has_horizontal())
+            {
+                switch(style.alignment_.get_horizontal())
+                {
+                    case alignment::horizontal_alignment::center:
+                        alignment_node.add_attribute("horizontal", "center");
+                        break;
+                    case alignment::horizontal_alignment::center_continuous:
+                        alignment_node.add_attribute("horizontal", "center_continuous");
+                        break;
+                    case alignment::horizontal_alignment::general:
+                        alignment_node.add_attribute("horizontal", "general");
+                        break;
+                    case alignment::horizontal_alignment::justify:
+                        alignment_node.add_attribute("horizontal", "justify");
+                        break;
+                    case alignment::horizontal_alignment::left:
+                        alignment_node.add_attribute("horizontal", "left");
+                        break;
+                    case alignment::horizontal_alignment::right:
+                        alignment_node.add_attribute("horizontal", "right");
+                        break;
+                    default:
+                        throw std::runtime_error("invalid alignment");
+                }
+            }
+            
+            if(style.alignment_.get_wrap_text())
+            {
+                alignment_node.add_attribute("wrapText", 1);
+            }
+        }
+    }
+
+    auto cell_styles_node = style_sheet_node.add_child("cellStyles");
+    cell_styles_node.add_attribute("count", 1);
+    auto cell_style_node = cell_styles_node.add_child("cellStyle");
+    cell_style_node.add_attribute("name", "Normal");
+    cell_style_node.add_attribute("xfId", 0);
+    cell_style_node.add_attribute("builtinId", 0);
+
+    style_sheet_node.add_child("dxfs").add_attribute("count", 0);
+
+    auto table_styles_node = style_sheet_node.add_child("tableStyles");
+    table_styles_node.add_attribute("count", 0);
+    table_styles_node.add_attribute("defaultTableStyle", "TableStyleMedium2");
+    table_styles_node.add_attribute("defaultPivotStyle", "PivotStyleMedium9");
+    
+    auto colors_node = style_sheet_node.add_child("colors");
+    auto indexed_colors_node = colors_node.add_child("indexedColors");
+    
+    for(auto &c : wb_.get_colors())
+    {
+        indexed_colors_node.add_child("rgbColor").add_attribute("rgb", c.get_rgb_string());
+    }
+
+    auto ext_list_node = style_sheet_node.add_child("extLst");
+    auto ext_node = ext_list_node.add_child("ext");
+    ext_node.add_attribute("uri", "{EB79DEF2-80B8-43e5-95BD-54CBDDF9020C}");
+    ext_node.add_attribute("xmlns:x14", "http://schemas.microsoft.com/office/spreadsheetml/2009/9/main");
+    ext_node.add_child("x14:slicerStyles").add_attribute("defaultSlicerStyle", "SlicerStyleLight1");
+
+    return true;
+}
+
+bool style_serializer::write_number_formats(xml_node &number_formats_node) const
+{
+    number_formats_node.add_attribute("count", std::to_string(wb_.get_number_formats().size()));
+    
+    for(const auto &num_fmt : wb_.get_number_formats())
+    {
+        auto &num_fmt_node = number_formats_node.add_child("numFmt");
+        num_fmt_node.add_attribute("numFmtId", std::to_string(num_fmt.get_id()));
+        num_fmt_node.add_attribute("formatCode", num_fmt.get_format_string());
+    }
+    
+    return true;
+}
+    
+} // namespace xlnt
diff --git a/source/writer/workbook_writer.cpp b/source/s11n/workbook_serializer.cpp
similarity index 79%
rename from source/writer/workbook_writer.cpp
rename to source/s11n/workbook_serializer.cpp
index a5789f41..ed8834d2 100644
--- a/source/writer/workbook_writer.cpp
+++ b/source/s11n/workbook_serializer.cpp
@@ -1,27 +1,33 @@
-#include <set>
-#include <sstream>
-
-#include <xlnt/cell/cell.hpp>
-#include <xlnt/common/exceptions.hpp>
+#include <xlnt/s11n/workbook_serializer.hpp>
+#include <xlnt/common/datetime.hpp>
 #include <xlnt/common/relationship.hpp>
-#include <xlnt/common/zip_file.hpp>
+#include <xlnt/s11n/xml_document.hpp>
+#include <xlnt/s11n/xml_node.hpp>
 #include <xlnt/workbook/document_properties.hpp>
-#include <xlnt/workbook/named_range.hpp>
+#include <xlnt/workbook/manifest.hpp>
 #include <xlnt/workbook/workbook.hpp>
-#include <xlnt/worksheet/range.hpp>
-#include <xlnt/worksheet/range_reference.hpp>
-#include <xlnt/worksheet/worksheet.hpp>
-#include <xlnt/writer/manifest_writer.hpp>
-#include <xlnt/writer/relationship_writer.hpp>
-#include <xlnt/writer/theme_writer.hpp>
-#include <xlnt/writer/worksheet_writer.hpp>
-#include <xlnt/writer/workbook_writer.hpp>
 
 #include "detail/constants.hpp"
-#include "detail/include_pugixml.hpp"
 
 namespace {
     
+xlnt::datetime w3cdtf_to_datetime(const std::string &string)
+{
+    xlnt::datetime result(1900, 1, 1);
+    auto separator_index = string.find('-');
+    result.year = std::stoi(string.substr(0, separator_index));
+    result.month = std::stoi(string.substr(separator_index + 1, string.find('-', separator_index + 1)));
+    separator_index = string.find('-', separator_index + 1);
+    result.day = std::stoi(string.substr(separator_index + 1, string.find('T', separator_index + 1)));
+    separator_index = string.find('T', separator_index + 1);
+    result.hour = std::stoi(string.substr(separator_index + 1, string.find(':', separator_index + 1)));
+    separator_index = string.find(':', separator_index + 1);
+    result.minute = std::stoi(string.substr(separator_index + 1, string.find(':', separator_index + 1)));
+    separator_index = string.find(':', separator_index + 1);
+    result.second = std::stoi(string.substr(separator_index + 1, string.find('Z', separator_index + 1)));
+    return result;
+}
+    
 std::string fill(const std::string &string, std::size_t length = 2)
 {
     if(string.size() >= length)
@@ -40,8 +46,177 @@ std::string datetime_to_w3cdtf(const xlnt::datetime &dt)
 } // namespace
 
 namespace xlnt {
+    
+    /*
+std::vector<std::pair<std::string, std::string>> workbook_serializer::read_sheets(zip_file &archive)
+{
+    std::string ns;
+    
+    for(auto child : doc.children())
+    {
+        std::string name = child.name();
+        
+        if(name.find(':') != std::string::npos)
+        {
+            auto colon_index = name.find(':');
+            ns = name.substr(0, colon_index);
+            break;
+        }
+    }
+    
+    auto with_ns = [&](const std::string &base) { return ns.empty() ? base : ns + ":" + base; };
+    
+    auto root_node = doc.child(with_ns("workbook").c_str());
+    auto sheets_node = root_node.child(with_ns("sheets").c_str());
+    
+    std::vector<std::pair<std::string, std::string>> sheets;
+    
+    // store temp because pugixml iteration uses the internal char array multiple times
+    auto sheet_element_name = with_ns("sheet");
+    
+    for(auto sheet_node : sheets_node.children(sheet_element_name.c_str()))
+    {
+        std::string id = sheet_node.attribute("r:id").as_string();
+        std::string name = sheet_node.attribute("name").as_string();
+        sheets.push_back(std::make_pair(id, name));
+    }
+    
+    return sheets;
+}
+     */
 
-std::string write_shared_strings(const std::vector<std::string> &string_table)
+void workbook_serializer::read_properties_core(const xml_document &xml)
+{
+    auto &props = wb_.get_properties();
+    auto root_node = xml.root();
+    
+    props.excel_base_date = calendar::windows_1900;
+    
+    if(root_node.has_child("dc:creator"))
+    {
+        props.creator = root_node.get_child("dc:creator").get_text();
+    }
+    if(root_node.has_child("cp:lastModifiedBy"))
+    {
+        props.last_modified_by = root_node.get_child("cp:lastModifiedBy").get_text();
+    }
+    if(root_node.has_child("dcterms:created"))
+    {
+        std::string created_string = root_node.get_child("dcterms:created").get_text();
+        props.created = w3cdtf_to_datetime(created_string);
+    }
+    if(root_node.has_child("dcterms:modified"))
+    {
+        std::string modified_string = root_node.get_child("dcterms:modified").get_text();
+        props.modified = w3cdtf_to_datetime(modified_string);
+    }
+}
+
+std::string workbook_serializer::read_dimension(const std::string &xml_string)
+{
+    pugi::xml_document doc;
+    doc.load(xml_string.c_str());
+    auto root_node = doc.child("worksheet");
+    auto dimension_node = root_node.child("dimension");
+    std::string dimension = dimension_node.attribute("ref").as_string();
+    return dimension;
+}
+
+std::vector<relationship> workbook_serializer::read_relationships(zip_file &archive, const std::string &filename)
+{
+    auto filename_separator_index = filename.find_last_of('/');
+    auto basename = filename.substr(filename_separator_index + 1);
+    auto dirname = filename.substr(0, filename_separator_index);
+    auto rels_filename = dirname + "/_rels/" + basename + ".rels";
+    
+    pugi::xml_document doc;
+    auto content = archive.read(rels_filename);
+    doc.load(content.c_str());
+    
+    auto root_node = doc.child("Relationships");
+    
+    std::vector<relationship> relationships;
+    
+    for(auto relationship : root_node.children("Relationship"))
+    {
+        std::string id = relationship.attribute("Id").as_string();
+        std::string type = relationship.attribute("Type").as_string();
+        std::string target = relationship.attribute("Target").as_string();
+        
+        if(target[0] != '/' && target.substr(0, 2) != "..")
+        {
+            target = dirname + "/" + target;
+        }
+        
+        if(target[0] == '/')
+        {
+            target = target.substr(1);
+        }
+        
+        relationships.push_back(xlnt::relationship(type, id, target));
+    }
+    
+    return relationships;
+}
+
+std::string workbook_serializer::determine_document_type(const manifest &manifest)
+{
+    if(!manifest.has_override_type(constants::ArcWorkbook))
+    {
+        return "unsupported";
+    }
+    
+    std::string type = manifest.get_override_type(constants::ArcWorkbook);
+    
+    if(type == "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml")
+    {
+        return "excel";
+    }
+    else if(type == "application/vnd.openxmlformats-officedocument.presentationml.presentation.main+xml")
+    {
+        return "powerpoint";
+    }
+    else if(type == "application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml")
+    {
+        return "word";
+    }
+    
+    return "unsupported";
+}
+
+std::vector<std::pair<std::string, std::string>> workbook_serializer::detect_worksheets(zip_file &archive)
+{
+    static const std::string ValidWorksheet = "application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml";
+    
+    auto content_types = read_content_types(archive);
+    std::vector<std::string> valid_sheets;
+    
+    for(const auto &content_type : content_types)
+    {
+        if(content_type.second == ValidWorksheet)
+        {
+            valid_sheets.push_back(content_type.first);
+        }
+    }
+    
+    auto workbook_relationships = read_relationships(archive, "xl/workbook.xml");
+    std::vector<std::pair<std::string, std::string>> result;
+    
+    for(const auto &ws : read_sheets(archive))
+    {
+        auto rel = *std::find_if(workbook_relationships.begin(), workbook_relationships.end(), [&](const relationship &r) { return r.get_id() == ws.first; });
+        auto target = rel.get_target_uri();
+        
+        if(std::find(valid_sheets.begin(), valid_sheets.end(), "/" + target) != valid_sheets.end())
+        {
+            result.push_back({target, ws.second});
+        }
+    }
+    
+    return result;
+}
+
+std::string workbook_serializer::write_shared_strings(const std::vector<std::string> &string_table)
 {
     pugi::xml_document doc;
     auto root_node = doc.append_child("sst");
@@ -59,7 +234,7 @@ std::string write_shared_strings(const std::vector<std::string> &string_table)
     return ss.str();
 }
 
-std::string write_properties_core(const document_properties &prop)
+std::string workbook_serializer::write_properties_core(const document_properties &prop)
 {
     pugi::xml_document doc;
     auto root_node = doc.append_child("cp:coreProperties");
@@ -87,12 +262,12 @@ std::string write_properties_core(const document_properties &prop)
     return ss.str();
 }
 
-std::string write_worksheet_rels(worksheet ws)
+std::string workbook_serializer::write_worksheet_rels(worksheet ws)
 {
     return write_relationships(ws.get_relationships(), "");
 }
 
-std::string write_theme()
+std::string workbook_serializer::write_theme()
 {
     pugi::xml_document doc;
     auto theme_node = doc.append_child("a:theme");
@@ -578,12 +753,12 @@ std::string write_workbook(const workbook &wb)
     return ss.str();
 }
 
-std::string write_workbook_rels(const workbook &wb)
+std::string workbook_serializer::write_workbook_rels(const workbook &wb)
 {
     return write_relationships(wb.get_relationships(), "xl/");
 }
     
-std::string write_defined_names(const xlnt::workbook &wb)
+std::string workbook_serializer::write_defined_names(const xlnt::workbook &wb)
 {
     pugi::xml_document doc;
     auto names = doc.root().append_child("names");
diff --git a/source/s11n/worksheet_serializer.cpp b/source/s11n/worksheet_serializer.cpp
new file mode 100644
index 00000000..15488d13
--- /dev/null
+++ b/source/s11n/worksheet_serializer.cpp
@@ -0,0 +1,368 @@
+#include <xlnt/s11n/worksheet_serializer.hpp>
+#include <xlnt/cell/cell.hpp>
+#include <xlnt/cell/cell_reference.hpp>
+#include <xlnt/s11n/xml_document.hpp>
+#include <xlnt/s11n/xml_node.hpp>
+#include <xlnt/worksheet/range.hpp>
+#include <xlnt/worksheet/range_reference.hpp>
+
+#include "detail/constants.hpp"
+
+namespace {
+
+bool is_integral(long double d)
+{
+    return d == static_cast<long long int>(d);
+}
+    
+} // namepsace
+
+namespace xlnt {
+
+bool worksheet_serializer::write_worksheet(const worksheet ws, const std::vector<std::string> &string_table, xml_document &xml)
+{
+    ws.get_cell("A1");
+    
+    xml.add_namespace("", constants::Namespaces.at("spreadsheetml"));
+    xml.add_namespace("r", constants::Namespaces.at("r"));
+
+    auto &root_node = xml.root();
+    root_node.set_name("worksheet");
+    
+    auto &sheet_pr_node = root_node.add_child("sheetPr");
+    
+    if(!ws.get_page_setup().is_default())
+    {
+        auto &page_set_up_pr_node = sheet_pr_node.add_child("pageSetUpPr");
+        page_set_up_pr_node.add_attribute("fitToPage", ws.get_page_setup().fit_to_page() ? "1" : "0");
+    }
+    
+    auto &outline_pr_node = sheet_pr_node.add_child("outlinePr");
+    
+    outline_pr_node.add_attribute("summaryBelow", "1");
+    outline_pr_node.add_attribute("summaryRight", "1");
+    
+    auto &dimension_node = root_node.add_child("dimension");
+    dimension_node.add_attribute("ref", ws.calculate_dimension().to_string());
+    
+    auto &sheet_views_node = root_node.add_child("sheetViews");
+    auto &sheet_view_node = sheet_views_node.add_child("sheetView");
+    sheet_view_node.add_attribute("workbookViewId", "0");
+    
+    std::string active_pane = "bottomRight";
+    
+    if(ws.has_frozen_panes())
+    {
+        auto pane_node = sheet_view_node.add_child("pane");
+        
+        if(ws.get_frozen_panes().get_column_index() > 1)
+        {
+            pane_node.add_attribute("xSplit", std::to_string(ws.get_frozen_panes().get_column_index() - 1));
+            active_pane = "topRight";
+        }
+        
+        if(ws.get_frozen_panes().get_row() > 1)
+        {
+            pane_node.add_attribute("ySplit", std::to_string(ws.get_frozen_panes().get_row() - 1));
+            active_pane = "bottomLeft";
+        }
+        
+        if(ws.get_frozen_panes().get_row() > 1 && ws.get_frozen_panes().get_column_index() > 1)
+        {
+            auto top_right_node = sheet_view_node.add_child("selection");
+            top_right_node.add_attribute("pane", "topRight");
+            auto bottom_left_node = sheet_view_node.add_child("selection");
+            bottom_left_node.add_attribute("pane", "bottomLeft");
+            active_pane = "bottomRight";
+        }
+        
+        pane_node.add_attribute("topLeftCell", ws.get_frozen_panes().to_string());
+        pane_node.add_attribute("activePane", active_pane);
+        pane_node.add_attribute("state", "frozen");
+    }
+    
+    auto selection_node = sheet_view_node.add_child("selection");
+    
+    if(ws.has_frozen_panes())
+    {
+        if(ws.get_frozen_panes().get_row() > 1 && ws.get_frozen_panes().get_column_index() > 1)
+        {
+            selection_node.add_attribute("pane", "bottomRight");
+        }
+        else if(ws.get_frozen_panes().get_row() > 1)
+        {
+            selection_node.add_attribute("pane", "bottomLeft");
+        }
+        else if(ws.get_frozen_panes().get_column_index() > 1)
+        {
+            selection_node.add_attribute("pane", "topRight");
+        }
+    }
+    
+    std::string active_cell = "A1";
+    selection_node.add_attribute("activeCell", active_cell);
+    selection_node.add_attribute("sqref", active_cell);
+    
+    auto sheet_format_pr_node = root_node.add_child("sheetFormatPr");
+    sheet_format_pr_node.add_attribute("baseColWidth", "10");
+    sheet_format_pr_node.add_attribute("defaultRowHeight", "15");
+    
+    bool has_column_properties = false;
+    
+    for(auto column = ws.get_lowest_column(); column <= ws.get_highest_column(); column++)
+    {
+        if(ws.has_column_properties(column))
+        {
+            has_column_properties = true;
+            break;
+        }
+    }
+    
+    if(has_column_properties)
+    {
+        auto cols_node = root_node.add_child("cols");
+        
+        for(auto column = ws.get_lowest_column(); column <= ws.get_highest_column(); column++)
+        {
+            const auto &props = ws.get_column_properties(column);
+            
+            auto col_node = cols_node.add_child("col");
+            
+            col_node.add_attribute("min", std::to_string(column));
+            col_node.add_attribute("max", std::to_string(column));
+            col_node.add_attribute("width", std::to_string(props.width));
+            col_node.add_attribute("style", std::to_string(props.style));
+            col_node.add_attribute("customWidth", props.custom ? "1" : "0");
+        }
+    }
+    
+    std::unordered_map<std::string, std::string> hyperlink_references;
+    
+    auto sheet_data_node = root_node.add_child("sheetData");
+    
+    for(auto row : ws.rows())
+    {
+        row_t min = static_cast<row_t>(row.num_cells());
+        row_t max = 0;
+        bool any_non_null = false;
+        
+        for(auto cell : row)
+        {
+            min = std::min(min, cell_reference::column_index_from_string(cell.get_column()));
+            max = std::max(max, cell_reference::column_index_from_string(cell.get_column()));
+            
+            if(!cell.garbage_collectible())
+            {
+                any_non_null = true;
+            }
+        }
+        
+        if(!any_non_null)
+        {
+            continue;
+        }
+        
+        auto row_node = sheet_data_node.add_child("row");
+        
+        row_node.add_attribute("r", std::to_string(row.front().get_row()));
+        row_node.add_attribute("spans", (std::to_string(min) + ":" + std::to_string(max)));
+        
+        if(ws.has_row_properties(row.front().get_row()))
+        {
+            row_node.add_attribute("customHeight", "1");
+            auto height = ws.get_row_properties(row.front().get_row()).height;
+            
+            if(height == std::floor(height))
+            {
+                row_node.add_attribute("ht", std::to_string(static_cast<long long int>(height)) + ".0");
+            }
+            else
+            {
+                row_node.add_attribute("ht", std::to_string(height));
+            }
+        }
+        
+        //row_node.add_attribute("x14ac:dyDescent", 0.25);
+        
+        for(auto cell : row)
+        {
+            if(!cell.garbage_collectible())
+            {
+                if(cell.has_hyperlink())
+                {
+                    hyperlink_references[cell.get_hyperlink().get_id()] = cell.get_reference().to_string();
+                }
+                
+                auto cell_node = row_node.add_child("c");
+                cell_node.add_attribute("r", cell.get_reference().to_string());
+                
+                if(cell.get_data_type() == cell::type::string)
+                {
+                    if(cell.has_formula())
+                    {
+                        cell_node.add_attribute("t", "str");
+                        cell_node.add_child("f").set_text(cell.get_formula());
+                        cell_node.add_child("v").set_text(cell.to_string());
+                        
+                        continue;
+                    }
+                    
+                    int match_index = -1;
+                    
+                    for(std::size_t i = 0; i < string_table.size(); i++)
+                    {
+                        if(string_table[i] == cell.get_value<std::string>())
+                        {
+                            match_index = static_cast<int>(i);
+                            break;
+                        }
+                    }
+                    
+                    if(match_index == -1)
+                    {
+                        if(cell.get_value<std::string>().empty())
+                        {
+                            cell_node.add_attribute("t", "s");
+                        }
+                        else
+                        {
+                            cell_node.add_attribute("t", "inlineStr");
+                            auto inline_string_node = cell_node.add_child("is");
+                            inline_string_node.add_child("t").text().set(cell.get_value<std::string>());
+                        }
+                    }
+                    else
+                    {
+                        cell_node.add_attribute("t", "s");
+                        auto value_node = cell_node.add_child("v");
+                        value_node.text().set(match_index);
+                    }
+                }
+                else
+                {
+                    if(cell.get_data_type() != cell::type::null)
+                    {
+                        if(cell.get_data_type() == cell::type::boolean)
+                        {
+                            cell_node.add_attribute("t", "b");
+                            auto value_node = cell_node.add_child("v");
+                            value_node.text().set(cell.get_value<bool>() ? 1 : 0);
+                        }
+                        else if(cell.get_data_type() == cell::type::numeric)
+                        {
+                            if(cell.has_formula())
+                            {
+                                cell_node.add_child("f").text().set(cell.get_formula());
+                                cell_node.add_child("v").text().set(cell.to_string());
+                                continue;
+                            }
+                            
+                            cell_node.add_attribute("t", "n");
+                            auto value_node = cell_node.add_child("v");
+                            if(is_integral(cell.get_value<long double>()))
+                            {
+                                value_node.text().set(cell.get_value<long long>());
+                            }
+                            else
+                            {
+                                std::stringstream ss;
+                                ss.precision(20);
+                                ss << cell.get_value<long double>();
+                                ss.str();
+                                value_node.text().set(ss.str());
+                            }
+                        }
+                    }
+                    else if(cell.has_formula())
+                    {
+                        cell_node.add_child("f").text().set(cell.get_formula());
+                        cell_node.add_child("v");
+                        continue;
+                    }
+                }
+                
+                //if(cell.has_style())
+                {
+                    auto style_id = cell.get_style_id();
+                    cell_node.add_attribute("s", (int)style_id);
+                }
+            }
+        }
+    }
+    
+    if(ws.has_auto_filter())
+    {
+        auto auto_filter_node = root_node.add_child("autoFilter");
+        auto_filter_node.add_attribute("ref", ws.get_auto_filter().to_string());
+    }
+    
+    if(!ws.get_merged_ranges().empty())
+    {
+        auto merge_cells_node = root_node.add_child("mergeCells");
+        merge_cells_node.add_attribute("count", (unsigned int)ws.get_merged_ranges().size());
+        
+        for(auto merged_range : ws.get_merged_ranges())
+        {
+            auto merge_cell_node = merge_cells_node.add_child("mergeCell");
+            merge_cell_node.add_attribute("ref", merged_range.to_string());
+        }
+    }
+    
+    if(!ws.get_relationships().empty())
+    {
+        auto hyperlinks_node = root_node.add_child("hyperlinks");
+        
+        for(auto relationship : ws.get_relationships())
+        {
+            auto hyperlink_node = hyperlinks_node.add_child("hyperlink");
+            hyperlink_node.add_attribute("display", relationship.get_target_uri());
+            hyperlink_node.add_attribute("ref", hyperlink_references.at(relationship.get_id()));
+            hyperlink_node.add_attribute("r:id", relationship.get_id());
+        }
+    }
+    
+    if(!ws.get_page_setup().is_default())
+    {
+        auto print_options_node = root_node.add_child("printOptions");
+        print_options_node.add_attribute("horizontalCentered", ws.get_page_setup().get_horizontal_centered() ? 1 : 0);
+        print_options_node.add_attribute("verticalCentered", ws.get_page_setup().get_vertical_centered() ? 1 : 0);
+    }
+    
+    auto page_margins_node = root_node.add_child("pageMargins");
+    
+    page_margins_node.add_attribute("left", ws.get_page_margins().get_left());
+    page_margins_node.add_attribute("right", ws.get_page_margins().get_right());
+    page_margins_node.add_attribute("top", ws.get_page_margins().get_top());
+    page_margins_node.add_attribute("bottom", ws.get_page_margins().get_bottom());
+    page_margins_node.add_attribute("header", ws.get_page_margins().get_header());
+    page_margins_node.add_attribute("footer", ws.get_page_margins().get_footer());
+    
+    if(!ws.get_page_setup().is_default())
+    {
+        auto page_setup_node = root_node.add_child("pageSetup");
+        
+        std::string orientation_string = ws.get_page_setup().get_orientation() == page_setup::orientation::landscape ? "landscape" : "portrait";
+        page_setup_node.add_attribute("orientation", orientation_string);
+        page_setup_node.add_attribute("paperSize", (int)ws.get_page_setup().get_paper_size());
+        page_setup_node.add_attribute("fitToHeight", ws.get_page_setup().fit_to_height() ? 1 : 0);
+        page_setup_node.add_attribute("fitToWidth", ws.get_page_setup().fit_to_width() ? 1 : 0);
+    }
+    
+    if(!ws.get_header_footer().is_default())
+    {
+        auto header_footer_node = root_node.add_child("headerFooter");
+        auto odd_header_node = header_footer_node.add_child("oddHeader");
+        std::string header_text = "&L&\"Calibri,Regular\"&K000000Left Header Text&C&\"Arial,Regular\"&6&K445566Center Header Text&R&\"Arial,Bold\"&8&K112233Right Header Text";
+        odd_header_node.text().set(header_text);
+        auto odd_footer_node = header_footer_node.add_child("oddFooter");
+        std::string footer_text = "&L&\"Times New Roman,Regular\"&10&K445566Left Footer Text_x000D_And &D and &T&C&\"Times New Roman,Bold\"&12&K778899Center Footer Text &Z&F on &A&R&\"Times New Roman,Italic\"&14&KAABBCCRight Footer Text &P of &N";
+        odd_footer_node.text().set(footer_text);
+    }
+    
+    std::stringstream ss;
+    doc.save(ss);
+    
+    return ss.str();
+}
+
+} // namespace xlnt
diff --git a/source/s11n/xml_document.cpp b/source/s11n/xml_document.cpp
new file mode 100644
index 00000000..b316e6f1
--- /dev/null
+++ b/source/s11n/xml_document.cpp
@@ -0,0 +1,25 @@
+#include <xlnt/s11n/xml_document.hpp>
+
+namespace xlnt {
+
+void xml_document::set_encoding(const std::string &encoding)
+{
+    
+}
+
+void xml_document::add_namespace(const std::string &id, const std::string &uri)
+{
+    
+}
+
+xml_node &xml_document::root()
+{
+    return root_;
+}
+
+const xml_node &xml_document::root() const
+{
+    return root_;
+}
+
+} // namespace xlnt
\ No newline at end of file
diff --git a/source/s11n/xml_node.cpp b/source/s11n/xml_node.cpp
new file mode 100644
index 00000000..06239c83
--- /dev/null
+++ b/source/s11n/xml_node.cpp
@@ -0,0 +1,107 @@
+#include <xlnt/s11n/xml_node.hpp>
+
+namespace xlnt {
+
+xml_node::xml_node()
+{
+}
+
+xml_node::xml_node(const std::string &name)
+{
+    set_name(name);
+}
+
+std::string xml_node::get_name() const
+{
+    return name_;
+}
+
+void xml_node::set_name(const std::string &name)
+{
+    name_ = name;
+}
+
+bool xml_node::has_text() const
+{
+    return has_text_;
+}
+
+std::string xml_node::get_text() const
+{
+    return text_;
+}
+
+void xml_node::set_text(const std::string &text)
+{
+    text_ = text;
+    has_text_ = true;
+}
+
+const std::vector<xml_node> &xml_node::get_children() const
+{
+    return children_;
+}
+
+xml_node &xml_node::add_child(const xml_node &child)
+{
+    has_text_ = false;
+    text_.clear();
+    
+    children_.push_back(child);
+    return children_.back();
+}
+
+xml_node &xml_node::add_child(const std::string &child_name)
+{
+    return add_child(xml_node(child_name));
+}
+
+const std::vector<string_pair> &xml_node::get_attributes() const
+{
+    return attributes_;
+}
+
+void xml_node::add_attribute(const std::string &name, const std::string &value)
+{
+    attributes_.push_back(std::make_pair(name, value));
+}
+
+bool xml_node::has_attribute(const std::string &attribute_name) const
+{
+    return std::find(attributes_.begin(), attributes_.end(),
+        [&](const string_pair &p) { return p.first == attribute_name; }) != attributes_.end();
+}
+
+std::string xml_node::get_attribute(const std::string &attribute_name) const
+{
+    auto match = std::find(attributes_.begin(), attributes_.end(),
+        [&](const string_pair &p) { return p.first == attribute_name; });
+    
+    if(match == attributes_.end())
+    {
+        throw std::runtime_error("attribute doesn't exist: " + attribute_name);
+    }
+    
+    return match->second;
+}
+
+bool xml_node::has_child(const std::string &child_name) const
+{
+    return std::find(children_.begin(), children_.end(),
+        [&](const xml_node &n) { return n.get_name() == child_name; }) != children_.end();
+}
+
+const xml_node &xml_node::get_child(const std::string &child_name) const
+{
+    auto match = std::find(children_.begin(), children_.end(),
+        [&](const xml_node &n) { return n.get_name() == child_name; });
+    
+    if(match == attributes_.end())
+    {
+        throw std::runtime_error("child doesn't exist: " + child_name);
+    }
+    
+    return *match;
+}
+
+} // namespace xlnt
diff --git a/source/s11n/xml_serializer.cpp b/source/s11n/xml_serializer.cpp
new file mode 100644
index 00000000..f721c6ec
--- /dev/null
+++ b/source/s11n/xml_serializer.cpp
@@ -0,0 +1,85 @@
+#include <sstream>
+
+#include <xlnt/s11n/xml_serializer.hpp>
+#include <xlnt/s11n/xml_document.hpp>
+#include <xlnt/s11n/xml_node.hpp>
+
+#include "detail/include_pugixml.hpp"
+
+namespace {
+
+void serialize_node(const xlnt::xml_node &source, pugi::xml_node node)
+{
+    for(const auto &attribute : source.get_attributes())
+    {
+        node.append_attribute(attribute.first.c_str()).set_value(attribute.second.c_str());
+    }
+    
+    if(source.has_text())
+    {
+        node.text().set(source.get_text().c_str());
+    }
+    else
+    {
+        for(const auto &child : source.get_children())
+        {
+            pugi::xml_node child_node = node.append_child(child.get_name().c_str());
+            serialize_node(child, child_node);
+        }
+    }
+}
+
+xlnt::xml_node deserialize_node(const pugi::xml_node source)
+{
+    xlnt::xml_node node(source.name());
+    
+    for(const auto attribute : source.attributes())
+    {
+        node.add_attribute(attribute.name(), attribute.as_string());
+    }
+
+    if(source.text() != nullptr)
+    {
+        node.set_text(source.text().as_string());
+    }
+    else
+    {
+        for(const auto child : source.children())
+        {
+            node.add_child(deserialize_node(child));
+        }
+    }
+    
+    return node;
+}
+    
+} // namespace
+
+namespace xlnt {
+
+std::string xml_serializer::serialize(const xml_document &xml)
+{
+    pugi::xml_document doc;
+    
+    auto root = doc.root();
+    root.set_name(xml.root().get_name().c_str());
+    serialize_node(xml.root(), root);
+    
+    std::ostringstream ss;
+    doc.save(ss);
+    
+    return ss.str();
+}
+    
+xml_document xml_serializer::deserialize(const std::string &xml_string)
+{
+    pugi::xml_document doc;
+    doc.load(xml_string.c_str());
+    
+    xml_document result;
+    result.root() = deserialize_node(doc.root());
+    
+    return result;
+}
+    
+} // namespace xlnt
diff --git a/source/workbook/manifest.cpp b/source/workbook/manifest.cpp
new file mode 100644
index 00000000..01d64837
--- /dev/null
+++ b/source/workbook/manifest.cpp
@@ -0,0 +1,43 @@
+#include <xlnt/workbook/manifest.hpp>
+
+namespace xlnt {
+
+bool manifest::has_default_type(const std::string &extension) const
+{
+    return std::find_if(default_types_.begin(), default_types_.end(),
+        [&](const default_type &d) { return d.get_extension() == extension; }) != default_types_.end();
+}
+
+bool manifest::has_override_type(const std::string &part_name) const
+{
+    return std::find_if(override_types_.begin(), override_types_.end(),
+        [&](const override_type &d) { return d.get_part_name() == part_name; }) != override_types_.end();
+}
+
+std::string manifest::get_default_type(const std::string &extension) const
+{
+    auto match = std::find_if(default_types_.begin(), default_types_.end(),
+        [&](const default_type &d) { return d.get_extension() == extension; });
+    
+    if(match == default_types_.end())
+    {
+        throw std::runtime_error("no default type found for extension: " + extension);
+    }
+    
+    return match->get_content_type();
+}
+
+std::string manifest::get_override_type(const std::string &part_name) const
+{
+    auto match = std::find_if(override_types_.begin(), override_types_.end(),
+        [&](const override_type &d) { return d.get_part_name() == part_name; });
+    
+    if(match == override_types_.end())
+    {
+        throw std::runtime_error("no default type found for part name: " + part_name);
+    }
+    
+    return match->get_content_type();
+}
+
+} // namespace xlnt
diff --git a/source/workbook/workbook.cpp b/source/workbook/workbook.cpp
index 21812a9a..92a54129 100644
--- a/source/workbook/workbook.cpp
+++ b/source/workbook/workbook.cpp
@@ -836,5 +836,15 @@ std::vector<color> workbook::get_colors() const
 {
     return d_->colors_;
 }
+
+manifest &workbook::get_manifest()
+{
+    return d_->manifest_;
+}
     
+const manifest &workbook::get_manifest() const
+{
+    return d_->manifest_;
+}
+
 } // namespace xlnt
diff --git a/source/worksheet/worksheet.cpp b/source/worksheet/worksheet.cpp
index 8b841721..7b3b4b2a 100644
--- a/source/worksheet/worksheet.cpp
+++ b/source/worksheet/worksheet.cpp
@@ -73,7 +73,7 @@ std::vector<range_reference> worksheet::get_merged_ranges() const
     return d_->merged_cells_;
 }
 
-margins &worksheet::get_page_margins()
+const margins &worksheet::get_page_margins() const
 {
     return d_->page_margins_;
 }
@@ -103,7 +103,7 @@ void worksheet::unset_auto_filter()
     d_->auto_filter_ = range_reference(1, 1, 1, 1);
 }
 
-page_setup &worksheet::get_page_setup()
+const page_setup &worksheet::get_page_setup() const
 {
     return d_->page_setup_;
 }
diff --git a/source/writer/excel_writer.cpp b/source/writer/excel_writer.cpp
deleted file mode 100644
index 80d5b66c..00000000
--- a/source/writer/excel_writer.cpp
+++ /dev/null
@@ -1,152 +0,0 @@
-#include <unordered_set>
-
-#include <xlnt/cell/cell.hpp>
-#include <xlnt/cell/cell_reference.hpp>
-#include <xlnt/common/zip_file.hpp>
-#include <xlnt/workbook/workbook.hpp>
-#include <xlnt/worksheet/range.hpp>
-#include <xlnt/worksheet/range_reference.hpp>
-#include <xlnt/worksheet/worksheet.hpp>
-#include <xlnt/writer/excel_writer.hpp>
-#include <xlnt/writer/manifest_writer.hpp>
-#include <xlnt/writer/workbook_writer.hpp>
-#include <xlnt/writer/worksheet_writer.hpp>
-
-#include "detail/constants.hpp"
-
-namespace {
-
-std::vector<std::string> extract_all_strings(xlnt::workbook &wb)
-{
-    std::unordered_set<std::string> strings;
-    
-    for(auto ws : wb)
-    {
-        for(auto row : ws.rows())
-        {
-            for(auto cell : row)
-            {
-                if(cell.get_data_type() == xlnt::cell::type::string)
-                {
-                    strings.insert(cell.get_value<std::string>());
-                }
-            }
-        }
-    }
-    
-    return std::vector<std::string>(strings.begin(), strings.end());
-}
-
-} // namespace
-
-namespace xlnt {
-
-excel_writer::excel_writer(workbook &wb) : wb_(wb)
-{
-}
-
-void excel_writer::save(const std::string &filename, bool as_template)
-{
-    zip_file archive;
-    write_data(archive, as_template);
-    archive.save(filename);
-}
-
-void excel_writer::write_data(zip_file &archive, bool as_template)
-{
-    archive.writestr(constants::ArcRootRels, write_root_rels(wb_));
-    archive.writestr(constants::ArcWorkbookRels, write_workbook_rels(wb_));
-    archive.writestr(constants::ArcApp, write_properties_app(wb_));
-    archive.writestr(constants::ArcCore, write_properties_core(wb_.get_properties()));
-    
-    if(wb_.has_loaded_theme())
-    {
-        archive.writestr(constants::ArcTheme, wb_.get_loaded_theme());
-    }
-    else
-    {
-        archive.writestr(constants::ArcTheme, write_theme());
-    }
-    
-    archive.writestr(constants::ArcWorkbook, write_workbook(wb_));
-    
-    auto shared_strings = extract_all_strings(wb_);
-    
-    write_charts(archive);
-    write_images(archive);
-    write_shared_strings(archive, shared_strings);
-    write_worksheets(archive, shared_strings);
-    write_chartsheets(archive);
-    write_external_links(archive);
-    
-    style_writer style_writer_(wb_);
-    archive.writestr(constants::ArcStyles, style_writer_.write_table());
-    
-    auto manifest = write_content_types(wb_, as_template);
-    archive.writestr(constants::ArcContentTypes, manifest);
-}
-    
-void excel_writer::write_shared_strings(xlnt::zip_file &archive, const std::vector<std::string> &shared_strings)
-{
-    archive.writestr(constants::ArcSharedString, ::xlnt::write_shared_strings(shared_strings));
-}
-
-void excel_writer::write_images(zip_file &/*archive*/)
-{
-    
-}
-
-void excel_writer::write_charts(zip_file &/*archive*/)
-{
-    
-}
-
-void excel_writer::write_chartsheets(zip_file &/*archive*/)
-{
-    
-}
-
-void excel_writer::write_worksheets(zip_file &archive, const std::vector<std::string> &shared_strings)
-{
-    std::size_t index = 0;
-    
-    for(auto ws : wb_)
-    {
-        for(auto relationship : wb_.get_relationships())
-        {
-            if(relationship.get_type() == relationship::type::worksheet &&
-               workbook::index_from_ws_filename(relationship.get_target_uri()) == index)
-            {
-                archive.writestr(relationship.get_target_uri(), write_worksheet(ws, shared_strings));
-                break;
-            }
-        }
-        
-        index++;
-    }
-}
-
-void excel_writer::write_external_links(zip_file &/*archive*/)
-{
-    
-}
-
-bool save_workbook(workbook &wb, const std::string &filename, bool as_template)
-{
-    excel_writer writer(wb);
-    writer.save(filename, as_template);
-    return true;
-}
-
-std::vector<std::uint8_t> save_virtual_workbook(xlnt::workbook &wb, bool as_template)
-{
-    zip_file archive;
-    excel_writer writer(wb);
-    writer.write_data(archive, as_template);
-    std::vector<std::uint8_t> buffer;
-    archive.save(buffer);
-    
-    return buffer;
-}
-
-} // namespace xlnt
diff --git a/source/writer/manifest_writer.cpp b/source/writer/manifest_writer.cpp
deleted file mode 100644
index 063addbe..00000000
--- a/source/writer/manifest_writer.cpp
+++ /dev/null
@@ -1,40 +0,0 @@
-#include <sstream>
-
-#include <xlnt/workbook/workbook.hpp>
-#include <xlnt/writer/manifest_writer.hpp>
-
-#include "detail/constants.hpp"
-#include "detail/include_pugixml.hpp"
-
-namespace xlnt {
-
-std::string write_content_types(const workbook &wb, bool /*as_template*/)
-{
-    pugi::xml_document doc;
-    auto root_node = doc.append_child("Types");
-    root_node.append_attribute("xmlns").set_value(constants::Namespaces.at("content-types").c_str());
-    
-    for(auto type : wb.get_content_types())
-    {
-        pugi::xml_node type_node;
-        
-        if (type.is_default)
-        {
-            type_node = root_node.append_child("Default");
-            type_node.append_attribute("Extension").set_value(type.extension.c_str());
-        }
-        else
-        {
-            type_node = root_node.append_child("Override");
-            type_node.append_attribute("PartName").set_value(type.part_name.c_str());
-        }
-        
-        type_node.append_attribute("ContentType").set_value(type.type.c_str());
-    }
-    
-    std::stringstream ss;
-    doc.save(ss);
-    return ss.str();
-}
-
-} // namespace xlnt
diff --git a/source/writer/relationship_writer.cpp b/source/writer/relationship_writer.cpp
deleted file mode 100644
index 833f4712..00000000
--- a/source/writer/relationship_writer.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-#include <sstream>
-
-#include <xlnt/common/relationship.hpp>
-#include <xlnt/writer/relationship_writer.hpp>
-
-#include "detail/constants.hpp"
-#include "detail/include_pugixml.hpp"
-
-namespace xlnt {
-
-std::string write_relationships(const std::vector<relationship> &relationships, const std::string &dir)
-{
-    pugi::xml_document doc;
-    
-    auto root_node = doc.append_child("Relationships");
-    root_node.append_attribute("xmlns").set_value(constants::Namespaces.at("relationships").c_str());
-    
-    for(auto relationship : relationships)
-    {
-        auto target = relationship.get_target_uri();
-        
-        if (dir != "" && target.substr(0, dir.size()) == dir)
-        {
-            target = target.substr(dir.size());
-        }
-        
-        auto app_props_node = root_node.append_child("Relationship");
-        
-        app_props_node.append_attribute("Id").set_value(relationship.get_id().c_str());
-        app_props_node.append_attribute("Target").set_value(target.c_str());
-        app_props_node.append_attribute("Type").set_value(relationship.get_type_string().c_str());
-        
-        if(relationship.get_target_mode() == target_mode::external)
-        {
-            app_props_node.append_attribute("TargetMode").set_value("External");
-        }
-    }
-    
-    std::stringstream ss;
-    doc.save(ss);
-    
-    return ss.str();
-}
-    
-}
diff --git a/source/writer/style_writer.cpp b/source/writer/style_writer.cpp
deleted file mode 100644
index d9fe52cc..00000000
--- a/source/writer/style_writer.cpp
+++ /dev/null
@@ -1,409 +0,0 @@
-#include <sstream>
-#include <pugixml.hpp>
-
-#include <xlnt/styles/alignment.hpp>
-#include <xlnt/styles/border.hpp>
-#include <xlnt/styles/fill.hpp>
-#include <xlnt/styles/font.hpp>
-#include <xlnt/styles/number_format.hpp>
-#include <xlnt/styles/protection.hpp>
-#include <xlnt/writer/style_writer.hpp>
-#include <xlnt/workbook/workbook.hpp>
-#include <xlnt/worksheet/worksheet.hpp>
-#include <xlnt/worksheet/range.hpp>
-#include <xlnt/cell/cell.hpp>
-
-namespace xlnt {
-
-style_writer::style_writer(xlnt::workbook &wb) : wb_(wb)
-{
-  
-}
-
-std::string style_writer::write_table() const
-{
-    pugi::xml_document doc;
-    auto style_sheet_node = doc.append_child("styleSheet");
-    style_sheet_node.append_attribute("xmlns").set_value("http://schemas.openxmlformats.org/spreadsheetml/2006/main");
-    style_sheet_node.append_attribute("xmlns:mc").set_value("http://schemas.openxmlformats.org/markup-compatibility/2006");
-    style_sheet_node.append_attribute("mc:Ignorable").set_value("x14ac");
-    style_sheet_node.append_attribute("xmlns:x14ac").set_value("http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac");
-    
-    auto num_fmts_node = style_sheet_node.append_child("numFmts");
-    auto num_fmts = wb_.get_number_formats();
-    num_fmts_node.append_attribute("count").set_value(static_cast<int>(num_fmts.size()));
-    
-    for(auto &num_fmt : num_fmts)
-    {
-        auto num_fmt_node = num_fmts_node.append_child("numFmt");
-        num_fmt_node.append_attribute("numFmtId").set_value(num_fmt.get_id());
-        num_fmt_node.append_attribute("formatCode").set_value(num_fmt.get_format_string().c_str());
-    }
-
-    auto fonts_node = style_sheet_node.append_child("fonts");
-    auto fonts = wb_.get_fonts();
-    if(fonts.empty())
-    {
-        fonts.push_back(font());
-    }
-    fonts_node.append_attribute("count").set_value(static_cast<int>(fonts.size()));
-    fonts_node.append_attribute("x14ac:knownFonts").set_value(1);
-    
-    for(auto &f : fonts)
-    {
-        auto font_node = fonts_node.append_child("font");
-        
-        if(f.is_bold())
-        {
-            auto bold_node = font_node.append_child("b");
-            bold_node.append_attribute("val").set_value(1);
-        }
-        
-        if(f.is_italic())
-        {
-            auto bold_node = font_node.append_child("i");
-            bold_node.append_attribute("val").set_value(1);
-        }
-        
-        if(f.is_underline())
-        {
-            auto bold_node = font_node.append_child("u");
-            
-            switch(f.get_underline())
-            {
-                case font::underline_style::single:
-                    bold_node.append_attribute("val").set_value("single");
-                    break;
-                default:
-                    break;
-            }
-        }
-        
-        if(f.is_strikethrough())
-        {
-            auto bold_node = font_node.append_child("strike");
-            bold_node.append_attribute("val").set_value(1);
-        }
-        
-        auto size_node = font_node.append_child("sz");
-        size_node.append_attribute("val").set_value(f.get_size());
-        
-        auto color_node = font_node.append_child("color");
-        
-        if(f.get_color().get_type() == color::type::indexed)
-        {
-            color_node.append_attribute("indexed").set_value(static_cast<unsigned int>(f.get_color().get_index()));
-        }
-        else if(f.get_color().get_type() == color::type::theme)
-        {
-            color_node.append_attribute("theme").set_value(static_cast<unsigned int>(f.get_color().get_theme()));
-        }
-        
-        auto name_node = font_node.append_child("name");
-        name_node.append_attribute("val").set_value(f.get_name().c_str());
-        
-        if(f.has_family())
-        {
-            auto family_node = font_node.append_child("family");
-            family_node.append_attribute("val").set_value(2);
-        }
-        
-        if(f.has_scheme())
-        {
-            auto scheme_node = font_node.append_child("scheme");
-            scheme_node.append_attribute("val").set_value("minor");
-        }
-    }
-
-    auto fills_node = style_sheet_node.append_child("fills");
-    const auto &fills = wb_.get_fills();
-    fills_node.append_attribute("count").set_value(static_cast<unsigned int>(fills.size()));
-    
-    for(auto &fill_ : fills)
-    {
-        auto fill_node = fills_node.append_child("fill");
-        
-        if(fill_.get_type() == fill::type::pattern)
-        {
-            auto pattern_fill_node = fill_node.append_child("patternFill");
-            auto type_string = fill_.get_pattern_type_string();
-            pattern_fill_node.append_attribute("patternType").set_value(type_string.c_str());
-            
-            if(fill_.has_foreground_color())
-            {
-                auto fg_color_node = pattern_fill_node.append_child("fgColor");
-                
-                switch(fill_.get_foreground_color().get_type())
-                {
-                    case color::type::auto_: fg_color_node.append_attribute("auto").set_value(fill_.get_foreground_color().get_auto()); break;
-                    case color::type::theme: fg_color_node.append_attribute("theme").set_value(fill_.get_foreground_color().get_theme()); break;
-                    case color::type::indexed: fg_color_node.append_attribute("indexed").set_value(fill_.get_foreground_color().get_index()); break;
-                    default: throw std::runtime_error("bad type");
-                }
-            }
-            
-            if(fill_.has_background_color())
-            {
-                auto bg_color_node = pattern_fill_node.append_child("bgColor");
-                
-                switch(fill_.get_background_color().get_type())
-                {
-                    case color::type::auto_: bg_color_node.append_attribute("auto").set_value(fill_.get_background_color().get_auto()); break;
-                    case color::type::theme: bg_color_node.append_attribute("theme").set_value(fill_.get_background_color().get_theme()); break;
-                    case color::type::indexed: bg_color_node.append_attribute("indexed").set_value(fill_.get_background_color().get_index()); break;
-                    default: throw std::runtime_error("bad type");
-                }
-            }
-        }
-        else if(fill_.get_type() == fill::type::solid)
-        {
-            auto solid_fill_node = fill_node.append_child("solidFill");
-            solid_fill_node.append_child("color");
-        }
-        else if(fill_.get_type() == fill::type::gradient)
-        {
-            auto gradient_fill_node = fill_node.append_child("gradientFill");
-            
-            if(fill_.get_gradient_type_string() == "linear")
-            {
-                gradient_fill_node.append_attribute("degree").set_value(fill_.get_rotation());
-            }
-            else if(fill_.get_gradient_type_string() == "path")
-            {
-                gradient_fill_node.append_attribute("left").set_value(fill_.get_gradient_left());
-                gradient_fill_node.append_attribute("right").set_value(fill_.get_gradient_right());
-                gradient_fill_node.append_attribute("top").set_value(fill_.get_gradient_top());
-                gradient_fill_node.append_attribute("bottom").set_value(fill_.get_gradient_bottom());
-                
-                auto start_node = gradient_fill_node.append_child("stop");
-                start_node.append_attribute("position").set_value(0);
-                
-                auto end_node = gradient_fill_node.append_child("stop");
-                end_node.append_attribute("position").set_value(1);
-            }
-        }
-    }
-
-    auto borders_node = style_sheet_node.append_child("borders");
-    const auto &borders = wb_.get_borders();
-    borders_node.append_attribute("count").set_value(static_cast<unsigned int>(borders.size()));
-    
-    for(const auto &border_ : borders)
-    {
-        auto border_node = borders_node.append_child("border");
-        
-        std::vector<std::tuple<std::string, const side, bool>> sides;
-        sides.push_back(std::make_tuple("start", border_.start, border_.start_assigned));
-        sides.push_back(std::make_tuple("end", border_.end, border_.end_assigned));
-        sides.push_back(std::make_tuple("left", border_.left, border_.left_assigned));
-        sides.push_back(std::make_tuple("right", border_.right, border_.right_assigned));
-        sides.push_back(std::make_tuple("top", border_.top, border_.top_assigned));
-        sides.push_back(std::make_tuple("bottom", border_.bottom, border_.bottom_assigned));
-        sides.push_back(std::make_tuple("diagonal", border_.diagonal, border_.diagonal_assigned));
-        sides.push_back(std::make_tuple("vertical", border_.vertical, border_.vertical_assigned));
-        sides.push_back(std::make_tuple("horizontal", border_.horizontal, border_.horizontal_assigned));
-        
-        for(const auto &side_tuple : sides)
-        {
-            std::string name = std::get<0>(side_tuple);
-            const side side_ = std::get<1>(side_tuple);
-            bool assigned = std::get<2>(side_tuple);
-            
-            if(assigned)
-            {
-                auto side_node = border_node.append_child(name.c_str());
-                
-                if(side_.is_style_assigned())
-                {
-                    auto style_attribute = side_node.append_attribute("style");
-                    
-                    switch(side_.get_style())
-                    {
-                        case border_style::none: style_attribute.set_value("none"); break;
-                        case border_style::dashdot : style_attribute.set_value("dashdot"); break;
-                        case border_style::dashdotdot : style_attribute.set_value("dashdotdot"); break;
-                        case border_style::dashed : style_attribute.set_value("dashed"); break;
-                        case border_style::dotted : style_attribute.set_value("dotted"); break;
-                        case border_style::double_ : style_attribute.set_value("double"); break;
-                        case border_style::hair : style_attribute.set_value("hair"); break;
-                        case border_style::medium : style_attribute.set_value("thin"); break;
-                        case border_style::mediumdashdot: style_attribute.set_value("mediumdashdot"); break;
-                        case border_style::mediumdashdotdot: style_attribute.set_value("mediumdashdotdot"); break;
-                        case border_style::mediumdashed: style_attribute.set_value("mediumdashed"); break;
-                        case border_style::slantdashdot: style_attribute.set_value("slantdashdot"); break;
-                        case border_style::thick: style_attribute.set_value("thick"); break;
-                        case border_style::thin: style_attribute.set_value("thin"); break;
-                        default: throw std::runtime_error("invalid style");
-                    }
-                }
-                
-                if(side_.is_color_assigned())
-                {
-                    auto color_node = side_node.append_child("color");
-                    
-                    if(side_.get_color_type() == side::color_type::indexed)
-                    {
-                        color_node.append_attribute("indexed").set_value((int)side_.get_color());
-                    }
-                    else if(side_.get_color_type() == side::color_type::theme)
-                    {
-                        color_node.append_attribute("indexed").set_value((int)side_.get_color());
-                    }
-                    else
-                    {
-                        throw std::runtime_error("invalid color type");
-                    }
-                }
-            }
-        }
-    }
-
-    auto cell_style_xfs_node = style_sheet_node.append_child("cellStyleXfs");
-    cell_style_xfs_node.append_attribute("count").set_value(1);
-    auto style_xf_node = cell_style_xfs_node.append_child("xf");
-    style_xf_node.append_attribute("numFmtId").set_value(0);
-    style_xf_node.append_attribute("fontId").set_value(0);
-    style_xf_node.append_attribute("fillId").set_value(0);
-    style_xf_node.append_attribute("borderId").set_value(0);
-    
-    auto cell_xfs_node = style_sheet_node.append_child("cellXfs");
-    const auto &styles = wb_.get_styles();
-    cell_xfs_node.append_attribute("count").set_value(static_cast<int>(styles.size()));
-    
-    for(auto &style : styles)
-    {
-        auto xf_node = cell_xfs_node.append_child("xf");
-        xf_node.append_attribute("numFmtId").set_value(style.get_number_format().get_id());
-        xf_node.append_attribute("fontId").set_value((int)style.get_font_id());
-        
-        if(style.fill_apply_)
-        {
-            xf_node.append_attribute("fillId").set_value((int)style.get_fill_id());
-        }
-        
-        if(style.border_apply_)
-        {
-            xf_node.append_attribute("borderId").set_value((int)style.get_border_id());
-        }
-        
-        xf_node.append_attribute("applyNumberFormat").set_value(style.number_format_apply_ ? 1 : 0);
-        xf_node.append_attribute("applyFont").set_value(style.font_apply_ ? 1 : 0);
-        xf_node.append_attribute("applyFill").set_value(style.fill_apply_ ? 1 : 0);
-        xf_node.append_attribute("applyBorder").set_value(style.border_apply_ ? 1 : 0);
-        xf_node.append_attribute("applyAlignment").set_value(style.alignment_apply_ ? 1 : 0);
-        xf_node.append_attribute("applyProtection").set_value(style.protection_apply_ ? 1 : 0);
-        
-        if(style.alignment_apply_)
-        {
-            auto alignment_node = xf_node.append_child("alignment");
-            
-            if(style.alignment_.has_vertical())
-            {
-                switch(style.alignment_.get_vertical())
-                {
-                    case alignment::vertical_alignment::bottom:
-                        alignment_node.append_attribute("vertical").set_value("bottom");
-                        break;
-                    case alignment::vertical_alignment::center:
-                        alignment_node.append_attribute("vertical").set_value("center");
-                        break;
-                    case alignment::vertical_alignment::justify:
-                        alignment_node.append_attribute("vertical").set_value("justify");
-                        break;
-                    case alignment::vertical_alignment::top:
-                        alignment_node.append_attribute("vertical").set_value("top");
-                        break;
-                    default:
-                        throw std::runtime_error("invalid alignment");
-                }
-            }
-            
-            if(style.alignment_.has_horizontal())
-            {
-                switch(style.alignment_.get_horizontal())
-                {
-                    case alignment::horizontal_alignment::center:
-                        alignment_node.append_attribute("horizontal").set_value("center");
-                        break;
-                    case alignment::horizontal_alignment::center_continuous:
-                        alignment_node.append_attribute("horizontal").set_value("center_continuous");
-                        break;
-                    case alignment::horizontal_alignment::general:
-                        alignment_node.append_attribute("horizontal").set_value("general");
-                        break;
-                    case alignment::horizontal_alignment::justify:
-                        alignment_node.append_attribute("horizontal").set_value("justify");
-                        break;
-                    case alignment::horizontal_alignment::left:
-                        alignment_node.append_attribute("horizontal").set_value("left");
-                        break;
-                    case alignment::horizontal_alignment::right:
-                        alignment_node.append_attribute("horizontal").set_value("right");
-                        break;
-                    default:
-                        throw std::runtime_error("invalid alignment");
-                }
-            }
-            
-            if(style.alignment_.get_wrap_text())
-            {
-                alignment_node.append_attribute("wrapText").set_value(1);
-            }
-        }
-    }
-
-    auto cell_styles_node = style_sheet_node.append_child("cellStyles");
-    cell_styles_node.append_attribute("count").set_value(1);
-    auto cell_style_node = cell_styles_node.append_child("cellStyle");
-    cell_style_node.append_attribute("name").set_value("Normal");
-    cell_style_node.append_attribute("xfId").set_value(0);
-    cell_style_node.append_attribute("builtinId").set_value(0);
-
-    style_sheet_node.append_child("dxfs").append_attribute("count").set_value(0);
-
-    auto table_styles_node = style_sheet_node.append_child("tableStyles");
-    table_styles_node.append_attribute("count").set_value(0);
-    table_styles_node.append_attribute("defaultTableStyle").set_value("TableStyleMedium2");
-    table_styles_node.append_attribute("defaultPivotStyle").set_value("PivotStyleMedium9");
-    
-    auto colors_node = style_sheet_node.append_child("colors");
-    auto indexed_colors_node = colors_node.append_child("indexedColors");
-    
-    for(auto &c : wb_.get_colors())
-    {
-        indexed_colors_node.append_child("rgbColor").append_attribute("rgb").set_value(c.get_rgb_string().c_str());
-    }
-
-    auto ext_list_node = style_sheet_node.append_child("extLst");
-    auto ext_node = ext_list_node.append_child("ext");
-    ext_node.append_attribute("uri").set_value("{EB79DEF2-80B8-43e5-95BD-54CBDDF9020C}");
-    ext_node.append_attribute("xmlns:x14").set_value("http://schemas.microsoft.com/office/spreadsheetml/2009/9/main");
-    ext_node.append_child("x14:slicerStyles").append_attribute("defaultSlicerStyle").set_value("SlicerStyleLight1");
-
-    std::stringstream ss;
-    doc.save(ss);
-
-    return ss.str();
-}
-
-std::string style_writer::write_number_formats()
-{
-    pugi::xml_document doc;
-
-    auto root = doc.append_child("styleSheet");
-    root.append_attribute("xmlns").set_value("http://schemas.openxmlformats.org/spreadsheetml/2006/main");
-    
-    auto num_fmts_node = root.append_child("numFmts");
-    num_fmts_node.append_attribute("count").set_value(1);
-    
-    auto num_fmt_node = num_fmts_node.append_child("numFmt");
-    num_fmt_node.append_attribute("formatCode").set_value("YYYY");
-    num_fmt_node.append_attribute("numFmtId").set_value(164);
-    
-    std::stringstream ss;
-    doc.save(ss);
-    
-    return ss.str();
-}
-    
-} // namespace xlnt
diff --git a/source/writer/worksheet_writer.cpp b/source/writer/worksheet_writer.cpp
deleted file mode 100644
index eb799e11..00000000
--- a/source/writer/worksheet_writer.cpp
+++ /dev/null
@@ -1,369 +0,0 @@
-#include <algorithm>
-#include <array>
-#include <sstream>
-
-#include <xlnt/cell/cell.hpp>
-#include <xlnt/cell/cell_reference.hpp>
-#include <xlnt/styles/border.hpp>
-#include <xlnt/styles/fill.hpp>
-#include <xlnt/styles/font.hpp>
-#include <xlnt/styles/number_format.hpp>
-#include <xlnt/workbook/workbook.hpp>
-#include <xlnt/worksheet/range.hpp>
-#include <xlnt/worksheet/range_reference.hpp>
-#include <xlnt/worksheet/worksheet.hpp>
-#include <xlnt/writer/worksheet_writer.hpp>
-
-#include "detail/constants.hpp"
-#include "detail/include_pugixml.hpp"
-
-namespace {
-
-bool is_integral(long double d)
-{
-    return d == static_cast<long long int>(d);
-}
-    
-} // namepsace
-
-namespace xlnt {
-
-std::string write_worksheet(worksheet ws, const std::vector<std::string> &string_table)
-{
-    ws.get_cell("A1");
-    
-    pugi::xml_document doc;
-    auto root_node = doc.append_child("worksheet");
-    root_node.append_attribute("xmlns").set_value(constants::Namespaces.at("spreadsheetml").c_str());
-    root_node.append_attribute("xmlns:r").set_value(constants::Namespaces.at("r").c_str());
-    auto sheet_pr_node = root_node.append_child("sheetPr");
-    auto outline_pr_node = sheet_pr_node.append_child("outlinePr");
-    if(!ws.get_page_setup().is_default())
-    {
-        auto page_set_up_pr_node = sheet_pr_node.append_child("pageSetUpPr");
-        page_set_up_pr_node.append_attribute("fitToPage").set_value(ws.get_page_setup().fit_to_page() ? 1 : 0);
-    }
-    outline_pr_node.append_attribute("summaryBelow").set_value(1);
-    outline_pr_node.append_attribute("summaryRight").set_value(1);
-    auto dimension_node = root_node.append_child("dimension");
-    dimension_node.append_attribute("ref").set_value(ws.calculate_dimension().to_string().c_str());
-    auto sheet_views_node = root_node.append_child("sheetViews");
-    auto sheet_view_node = sheet_views_node.append_child("sheetView");
-    sheet_view_node.append_attribute("workbookViewId").set_value(0);
-    
-    std::string active_pane = "bottomRight";
-    
-    if(ws.has_frozen_panes())
-    {
-        auto pane_node = sheet_view_node.append_child("pane");
-        
-        if(ws.get_frozen_panes().get_column_index() > 1)
-        {
-            pane_node.append_attribute("xSplit").set_value(ws.get_frozen_panes().get_column_index() - 1);
-            active_pane = "topRight";
-        }
-        
-        if(ws.get_frozen_panes().get_row() > 1)
-        {
-            pane_node.append_attribute("ySplit").set_value(ws.get_frozen_panes().get_row() - 1);
-            active_pane = "bottomLeft";
-        }
-        
-        if(ws.get_frozen_panes().get_row() > 1 && ws.get_frozen_panes().get_column_index() > 1)
-        {
-            auto top_right_node = sheet_view_node.append_child("selection");
-            top_right_node.append_attribute("pane").set_value("topRight");
-            auto bottom_left_node = sheet_view_node.append_child("selection");
-            bottom_left_node.append_attribute("pane").set_value("bottomLeft");
-            active_pane = "bottomRight";
-        }
-        
-        pane_node.append_attribute("topLeftCell").set_value(ws.get_frozen_panes().to_string().c_str());
-        pane_node.append_attribute("activePane").set_value(active_pane.c_str());
-        pane_node.append_attribute("state").set_value("frozen");
-    }
-    
-    auto selection_node = sheet_view_node.append_child("selection");
-    
-    if(ws.has_frozen_panes())
-    {
-        if(ws.get_frozen_panes().get_row() > 1 && ws.get_frozen_panes().get_column_index() > 1)
-        {
-            selection_node.append_attribute("pane").set_value("bottomRight");
-        }
-        else if(ws.get_frozen_panes().get_row() > 1)
-        {
-            selection_node.append_attribute("pane").set_value("bottomLeft");
-        }
-        else if(ws.get_frozen_panes().get_column_index() > 1)
-        {
-            selection_node.append_attribute("pane").set_value("topRight");
-        }
-    }
-    
-    std::string active_cell = "A1";
-    selection_node.append_attribute("activeCell").set_value(active_cell.c_str());
-    selection_node.append_attribute("sqref").set_value(active_cell.c_str());
-    
-    auto sheet_format_pr_node = root_node.append_child("sheetFormatPr");
-    sheet_format_pr_node.append_attribute("baseColWidth").set_value(10);
-    sheet_format_pr_node.append_attribute("defaultRowHeight").set_value(15);
-    
-    bool has_column_properties = false;
-    
-    for(auto column = ws.get_lowest_column(); column <= ws.get_highest_column(); column++)
-    {
-        if(ws.has_column_properties(column))
-        {
-            has_column_properties = true;
-            break;
-        }
-    }
-    
-    if(has_column_properties)
-    {
-        auto cols_node = root_node.append_child("cols");
-        
-        for(auto column = ws.get_lowest_column(); column <= ws.get_highest_column(); column++)
-        {
-            const auto &props = ws.get_column_properties(column);
-            
-            auto col_node = cols_node.append_child("col");
-            
-            col_node.append_attribute("min").set_value(column);
-            col_node.append_attribute("max").set_value(column);
-            col_node.append_attribute("width").set_value(props.width);
-            col_node.append_attribute("style").set_value(static_cast<unsigned long long>(props.style));
-            col_node.append_attribute("customWidth").set_value(props.custom ? 1 : 0);
-        }
-    }
-    
-    std::unordered_map<std::string, std::string> hyperlink_references;
-    
-    auto sheet_data_node = root_node.append_child("sheetData");
-    
-    for(auto row : ws.rows())
-    {
-        row_t min = static_cast<row_t>(row.num_cells());
-        row_t max = 0;
-        bool any_non_null = false;
-        
-        for(auto cell : row)
-        {
-            min = std::min(min, cell_reference::column_index_from_string(cell.get_column()));
-            max = std::max(max, cell_reference::column_index_from_string(cell.get_column()));
-            
-            if(!cell.garbage_collectible())
-            {
-                any_non_null = true;
-            }
-        }
-        
-        if(!any_non_null)
-        {
-            continue;
-        }
-        
-        auto row_node = sheet_data_node.append_child("row");
-        
-        row_node.append_attribute("r").set_value(row.front().get_row());
-        row_node.append_attribute("spans").set_value((std::to_string(min) + ":" + std::to_string(max)).c_str());
-        
-        if(ws.has_row_properties(row.front().get_row()))
-        {
-            row_node.append_attribute("customHeight").set_value(1);
-            auto height = ws.get_row_properties(row.front().get_row()).height;
-            
-            if(height == std::floor(height))
-            {
-                row_node.append_attribute("ht").set_value((std::to_string((int)height) + ".0").c_str());
-            }
-            else
-            {
-                row_node.append_attribute("ht").set_value(height);
-            }
-        }
-        
-        //row_node.append_attribute("x14ac:dyDescent").set_value(0.25);
-        
-        for(auto cell : row)
-        {
-            if(!cell.garbage_collectible())
-            {
-                if(cell.has_hyperlink())
-                {
-                    hyperlink_references[cell.get_hyperlink().get_id()] = cell.get_reference().to_string();
-                }
-                
-                auto cell_node = row_node.append_child("c");
-                cell_node.append_attribute("r").set_value(cell.get_reference().to_string().c_str());
-                
-                if(cell.get_data_type() == cell::type::string)
-                {
-                    if(cell.has_formula())
-                    {
-                        cell_node.append_attribute("t").set_value("str");
-                        cell_node.append_child("f").text().set(cell.get_formula().c_str());
-                        cell_node.append_child("v").text().set(cell.to_string().c_str());
-                        continue;
-                    }
-                    
-                    int match_index = -1;
-                    
-                    for(std::size_t i = 0; i < string_table.size(); i++)
-                    {
-                        if(string_table[i] == cell.get_value<std::string>())
-                        {
-                            match_index = static_cast<int>(i);
-                            break;
-                        }
-                    }
-                    
-                    if(match_index == -1)
-                    {
-                        if(cell.get_value<std::string>().empty())
-                        {
-                            cell_node.append_attribute("t").set_value("s");
-                        }
-                        else
-                        {
-                            cell_node.append_attribute("t").set_value("inlineStr");
-                            auto inline_string_node = cell_node.append_child("is");
-                            inline_string_node.append_child("t").text().set(cell.get_value<std::string>().c_str());
-                        }
-                    }
-                    else
-                    {
-                        cell_node.append_attribute("t").set_value("s");
-                        auto value_node = cell_node.append_child("v");
-                        value_node.text().set(match_index);
-                    }
-                }
-                else
-                {
-                    if(cell.get_data_type() != cell::type::null)
-                    {
-                        if(cell.get_data_type() == cell::type::boolean)
-                        {
-                            cell_node.append_attribute("t").set_value("b");
-                            auto value_node = cell_node.append_child("v");
-                            value_node.text().set(cell.get_value<bool>() ? 1 : 0);
-                        }
-                        else if(cell.get_data_type() == cell::type::numeric)
-                        {
-                            if(cell.has_formula())
-                            {
-                                cell_node.append_child("f").text().set(cell.get_formula().c_str());
-                                cell_node.append_child("v").text().set(cell.to_string().c_str());
-                                continue;
-                            }
-                            
-                            cell_node.append_attribute("t").set_value("n");
-                            auto value_node = cell_node.append_child("v");
-                            if(is_integral(cell.get_value<long double>()))
-                            {
-                                value_node.text().set(cell.get_value<long long>());
-                            }
-                            else
-                            {
-                                std::stringstream ss;
-                                ss.precision(20);
-                                ss << cell.get_value<long double>();
-                                ss.str();
-                                value_node.text().set(ss.str().c_str());
-                            }
-                        }
-                    }
-                    else if(cell.has_formula())
-                    {
-                        cell_node.append_child("f").text().set(cell.get_formula().c_str());
-                        cell_node.append_child("v");
-                        continue;
-                    }
-                }
-                
-                //if(cell.has_style())
-                {
-                    auto style_id = cell.get_style_id();
-                    cell_node.append_attribute("s").set_value((int)style_id);
-                }
-            }
-        }
-    }
-    
-    if(ws.has_auto_filter())
-    {
-        auto auto_filter_node = root_node.append_child("autoFilter");
-        auto_filter_node.append_attribute("ref").set_value(ws.get_auto_filter().to_string().c_str());
-    }
-    
-    if(!ws.get_merged_ranges().empty())
-    {
-        auto merge_cells_node = root_node.append_child("mergeCells");
-        merge_cells_node.append_attribute("count").set_value((unsigned int)ws.get_merged_ranges().size());
-        
-        for(auto merged_range : ws.get_merged_ranges())
-        {
-            auto merge_cell_node = merge_cells_node.append_child("mergeCell");
-            merge_cell_node.append_attribute("ref").set_value(merged_range.to_string().c_str());
-        }
-    }
-    
-    if(!ws.get_relationships().empty())
-    {
-        auto hyperlinks_node = root_node.append_child("hyperlinks");
-        
-        for(auto relationship : ws.get_relationships())
-        {
-            auto hyperlink_node = hyperlinks_node.append_child("hyperlink");
-            hyperlink_node.append_attribute("display").set_value(relationship.get_target_uri().c_str());
-            hyperlink_node.append_attribute("ref").set_value(hyperlink_references.at(relationship.get_id()).c_str());
-            hyperlink_node.append_attribute("r:id").set_value(relationship.get_id().c_str());
-        }
-    }
-    
-    if(!ws.get_page_setup().is_default())
-    {
-        auto print_options_node = root_node.append_child("printOptions");
-        print_options_node.append_attribute("horizontalCentered").set_value(ws.get_page_setup().get_horizontal_centered() ? 1 : 0);
-        print_options_node.append_attribute("verticalCentered").set_value(ws.get_page_setup().get_vertical_centered() ? 1 : 0);
-    }
-    
-    auto page_margins_node = root_node.append_child("pageMargins");
-    
-    page_margins_node.append_attribute("left").set_value(ws.get_page_margins().get_left());
-    page_margins_node.append_attribute("right").set_value(ws.get_page_margins().get_right());
-    page_margins_node.append_attribute("top").set_value(ws.get_page_margins().get_top());
-    page_margins_node.append_attribute("bottom").set_value(ws.get_page_margins().get_bottom());
-    page_margins_node.append_attribute("header").set_value(ws.get_page_margins().get_header());
-    page_margins_node.append_attribute("footer").set_value(ws.get_page_margins().get_footer());
-    
-    if(!ws.get_page_setup().is_default())
-    {
-        auto page_setup_node = root_node.append_child("pageSetup");
-        
-        std::string orientation_string = ws.get_page_setup().get_orientation() == page_setup::orientation::landscape ? "landscape" : "portrait";
-        page_setup_node.append_attribute("orientation").set_value(orientation_string.c_str());
-        page_setup_node.append_attribute("paperSize").set_value((int)ws.get_page_setup().get_paper_size());
-        page_setup_node.append_attribute("fitToHeight").set_value(ws.get_page_setup().fit_to_height() ? 1 : 0);
-        page_setup_node.append_attribute("fitToWidth").set_value(ws.get_page_setup().fit_to_width() ? 1 : 0);
-    }
-    
-    if(!ws.get_header_footer().is_default())
-    {
-        auto header_footer_node = root_node.append_child("headerFooter");
-        auto odd_header_node = header_footer_node.append_child("oddHeader");
-        std::string header_text = "&L&\"Calibri,Regular\"&K000000Left Header Text&C&\"Arial,Regular\"&6&K445566Center Header Text&R&\"Arial,Bold\"&8&K112233Right Header Text";
-        odd_header_node.text().set(header_text.c_str());
-        auto odd_footer_node = header_footer_node.append_child("oddFooter");
-        std::string footer_text = "&L&\"Times New Roman,Regular\"&10&K445566Left Footer Text_x000D_And &D and &T&C&\"Times New Roman,Bold\"&12&K778899Center Footer Text &Z&F on &A&R&\"Times New Roman,Italic\"&14&KAABBCCRight Footer Text &P of &N";
-        odd_footer_node.text().set(footer_text.c_str());
-    }
-    
-    std::stringstream ss;
-    doc.save(ss);
-    
-    return ss.str();
-}
-
-} // namespace xlnt
diff --git a/tests/test_cell.hpp b/tests/test_cell.hpp
index 558bb957..60f8a78c 100644
--- a/tests/test_cell.hpp
+++ b/tests/test_cell.hpp
@@ -22,6 +22,8 @@
 #include <xlnt/writer/excel_writer.hpp>
 #include <xlnt/reader/excel_reader.hpp>
 
+#include <xlnt/common/xml_tree.hpp>
+
 class test_cell : public CxxTest::TestSuite
 {
 private:
@@ -33,6 +35,13 @@ public:
         wb_guess_types.set_guess_types(true);
     }
     
+    void test_debug()
+    {
+        auto wb = xlnt::excel_reader::load_workbook("/Users/thomas/Development/xlnt/samples/formatting.xlsx");
+        wb.save("/Users/thomas/Development/xlnt/samples/formatting-rt.xlsx");
+        wb.save("/Users/thomas/Development/xlnt/samples/formatting-rt.zip");
+    }
+    
 	void test_infer_numeric()
 	{
 		auto ws = wb_guess_types.create_sheet();