diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3e436d35..52a52dee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,5 @@
 cmake_minimum_required(VERSION 2.8.6)
+cmake_policy(VERSION 2.8.6)
 project(toxcore)
 include(CTest)
 
@@ -41,7 +42,6 @@ include(ApiDsl)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)
 include(MacRpath)
-include(ModulePackage)
 
 set(CMAKE_MACOSX_RPATH ON)
 
@@ -76,77 +76,79 @@ macro(add_flag flag)
   add_cxxflag(${flag})
 endmacro()
   
-# Set standard version for compiler.
-add_cflag("-std=c99")
-add_cxxflag("-std=c++11")
+if(NOT "${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+  # Set standard version for compiler.
+  add_cflag("-std=c99")
+  add_cxxflag("-std=c++11")
 
-# Warn on non-ISO C.
-add_cflag("-pedantic")
+  # Warn on non-ISO C.
+  add_cflag("-pedantic")
 
-option(WARNINGS "Enable additional compiler warnings" ON)
-if(WARNINGS)
-  # Add all warning flags we can.
-  add_flag("-Wall")
-  add_flag("-Wextra")
-  add_flag("-Weverything")
+  option(WARNINGS "Enable additional compiler warnings" ON)
+  if(WARNINGS)
+    # Add all warning flags we can.
+    add_flag("-Wall")
+    add_flag("-Wextra")
+    add_flag("-Weverything")
 
-  # Disable specific warning flags for both C and C++.
-  add_flag("-Wno-cast-align")
-  add_flag("-Wno-conversion")
-  add_flag("-Wno-covered-switch-default")
-  add_flag("-Wno-documentation-deprecated-sync")
-  add_flag("-Wno-format-nonliteral")
-  add_flag("-Wno-missing-field-initializers")
-  add_flag("-Wno-missing-prototypes")
-  add_flag("-Wno-padded")
-  add_flag("-Wno-parentheses")
-  add_flag("-Wno-return-type")
-  add_flag("-Wno-sign-compare")
-  add_flag("-Wno-sign-conversion")
-  add_flag("-Wno-tautological-constant-out-of-range-compare")
-  add_flag("-Wno-type-limits")
-  add_flag("-Wno-undef")
-  add_flag("-Wno-unreachable-code")
-  add_flag("-Wno-unused-macros")
-  add_flag("-Wno-unused-parameter")
-  add_flag("-Wno-vla")
+    # Disable specific warning flags for both C and C++.
+    add_flag("-Wno-cast-align")
+    add_flag("-Wno-conversion")
+    add_flag("-Wno-covered-switch-default")
+    add_flag("-Wno-documentation-deprecated-sync")
+    add_flag("-Wno-format-nonliteral")
+    add_flag("-Wno-missing-field-initializers")
+    add_flag("-Wno-missing-prototypes")
+    add_flag("-Wno-padded")
+    add_flag("-Wno-parentheses")
+    add_flag("-Wno-return-type")
+    add_flag("-Wno-sign-compare")
+    add_flag("-Wno-sign-conversion")
+    add_flag("-Wno-tautological-constant-out-of-range-compare")
+    add_flag("-Wno-type-limits")
+    add_flag("-Wno-undef")
+    add_flag("-Wno-unreachable-code")
+    add_flag("-Wno-unused-macros")
+    add_flag("-Wno-unused-parameter")
+    add_flag("-Wno-vla")
 
-  # Disable specific warning flags for C.
-  add_cflag("-Wno-assign-enum")
-  add_cflag("-Wno-bad-function-cast")
-  add_cflag("-Wno-double-promotion")
-  add_cflag("-Wno-gnu-zero-variadic-macro-arguments")
-  add_cflag("-Wno-packed")
-  add_cflag("-Wno-reserved-id-macro")
-  add_cflag("-Wno-shadow")
-  add_cflag("-Wno-shorten-64-to-32")
-  add_cflag("-Wno-unreachable-code-return")
-  add_cflag("-Wno-unused-but-set-variable")
-  add_cflag("-Wno-used-but-marked-unused")
+    # Disable specific warning flags for C.
+    add_cflag("-Wno-assign-enum")
+    add_cflag("-Wno-bad-function-cast")
+    add_cflag("-Wno-double-promotion")
+    add_cflag("-Wno-gnu-zero-variadic-macro-arguments")
+    add_cflag("-Wno-packed")
+    add_cflag("-Wno-reserved-id-macro")
+    add_cflag("-Wno-shadow")
+    add_cflag("-Wno-shorten-64-to-32")
+    add_cflag("-Wno-unreachable-code-return")
+    add_cflag("-Wno-unused-but-set-variable")
+    add_cflag("-Wno-used-but-marked-unused")
 
-  # Disable specific warning flags for C++.
-  add_cxxflag("-Wno-c++11-compat")
-  add_cxxflag("-Wno-c++11-extensions")
-  add_cxxflag("-Wno-c++11-narrowing")
-  add_cxxflag("-Wno-c99-extensions")
-  add_cxxflag("-Wno-narrowing")
-  add_cxxflag("-Wno-old-style-cast")
-  add_cxxflag("-Wno-variadic-macros")
-  add_cxxflag("-Wno-vla-extension")
-endif()
+    # Disable specific warning flags for C++.
+    add_cxxflag("-Wno-c++11-compat")
+    add_cxxflag("-Wno-c++11-extensions")
+    add_cxxflag("-Wno-c++11-narrowing")
+    add_cxxflag("-Wno-c99-extensions")
+    add_cxxflag("-Wno-narrowing")
+    add_cxxflag("-Wno-old-style-cast")
+    add_cxxflag("-Wno-variadic-macros")
+    add_cxxflag("-Wno-vla-extension")
+  endif()
 
-option(ERROR_ON_WARNING "Make compilation error on a warning" OFF)
-if(ERROR_ON_WARNING)
-  # Set error-on-warn for C compilation. C++ compilation can't use this because
-  # treating 'c' input as 'c++' when in C++ mode is deprecated in clang and
-  # there is no way to turn off that warning.
-  add_cflag("-Werror")
-endif()
+  option(ERROR_ON_WARNING "Make compilation error on a warning" OFF)
+  if(ERROR_ON_WARNING)
+    # Set error-on-warn for C compilation. C++ compilation can't use this because
+    # treating 'c' input as 'c++' when in C++ mode is deprecated in clang and
+    # there is no way to turn off that warning.
+    add_cflag("-Werror")
+  endif()
 
-option(DEBUG "Enable assertions and other debugging facilities" OFF)
-if(DEBUG)
-  set(MIN_LOGGER_LEVEL DEBUG)
-  add_cflag("-g3")
+  option(DEBUG "Enable assertions and other debugging facilities" OFF)
+  if(DEBUG)
+    set(MIN_LOGGER_LEVEL DEBUG)
+    add_cflag("-g3")
+  endif()
 endif()
 
 option(TRACE "Enable TRACE level logging (expensive, for network debugging)" OFF)
@@ -166,32 +168,7 @@ if(ASAN)
   set(CMAKE_REQUIRED_LIBRARIES "${SAFE_CMAKE_REQUIRED_LIBRARIES}")
 endif()
 
-find_package(Threads   REQUIRED)
-
-find_library(NCURSES_LIBRARIES      ncurses       )
-find_library(UTIL_LIBRARIES         util          )
-find_library(RT_LIBRARIES           rt            )
-
-# For toxcore.
-pkg_use_module(LIBSODIUM  REQUIRED  libsodium     )
-
-# For toxav.
-pkg_use_module(OPUS                 opus          )
-pkg_use_module(VPX                  vpx           )
-
-# For tox-bootstrapd.
-pkg_use_module(LIBCONFIG            libconfig     )
-
-# For auto tests.
-pkg_use_module(CHECK                check         )
-
-# For tox-spectest.
-pkg_use_module(MSGPACK              msgpack       )
-
-# For av_test.
-pkg_use_module(OPENCV               opencv        )
-pkg_use_module(PORTAUDIO            portaudio-2.0 )
-pkg_use_module(SNDFILE              sndfile       )
+include(Dependencies)
 
 if(OPUS_FOUND AND VPX_FOUND)
   set(BUILD_TOXAV TRUE)
diff --git a/appveyor.yml b/appveyor.yml
new file mode 100644
index 00000000..879ebc10
--- /dev/null
+++ b/appveyor.yml
@@ -0,0 +1,13 @@
+install:
+- curl https://download.libsodium.org/libsodium/releases/libsodium-1.0.11-msvc.zip -o libsodium-1.0.11-msvc.zip
+- unzip libsodium-1.0.11-msvc.zip
+
+before_build:
+- cmake . -DBOOTSTRAP_DAEMON=OFF
+
+build:
+  project: INSTALL.vcxproj
+
+branches:
+  only:
+  - master
diff --git a/cmake/Dependencies.cmake b/cmake/Dependencies.cmake
new file mode 100644
index 00000000..338a4193
--- /dev/null
+++ b/cmake/Dependencies.cmake
@@ -0,0 +1,56 @@
+###############################################################################
+#
+# :: For UNIX-like systems that have pkg-config.
+#
+###############################################################################
+
+include(ModulePackage)
+
+find_package(Threads REQUIRED)
+
+find_library(NCURSES_LIBRARIES      ncurses      )
+find_library(UTIL_LIBRARIES         util         )
+find_library(RT_LIBRARIES           rt           )
+
+# For toxcore.
+pkg_use_module(LIBSODIUM            libsodium    )
+
+# For toxav.
+pkg_use_module(OPUS                 opus         )
+pkg_use_module(VPX                  vpx          )
+
+# For tox-bootstrapd.
+pkg_use_module(LIBCONFIG            libconfig    )
+
+# For auto tests.
+pkg_use_module(CHECK                check        )
+
+# For tox-spectest.
+pkg_use_module(MSGPACK              msgpack      )
+
+# For av_test.
+pkg_use_module(OPENCV               opencv       )
+pkg_use_module(PORTAUDIO            portaudio-2.0)
+pkg_use_module(SNDFILE              sndfile      )
+
+###############################################################################
+#
+# :: For Windows and other systems lacking pkg-config.
+#
+###############################################################################
+
+if(NOT LIBSODIUM_FOUND)
+  include_directories(include)
+  find_library(LIBSODIUM_LIBRARIES
+    NAMES
+      sodium
+      libsodium
+    PATHS
+      Win32/Release/v140/static
+      x64/Release/v140/static
+  )
+  if(LIBSODIUM_LIBRARIES)
+    set(LIBSODIUM_FOUND TRUE)
+  endif()
+  message("libsodium: ${LIBSODIUM_LIBRARIES}")
+endif()
diff --git a/cmake/ModulePackage.cmake b/cmake/ModulePackage.cmake
index 38f841ba..3a4eb9b9 100644
--- a/cmake/ModulePackage.cmake
+++ b/cmake/ModulePackage.cmake
@@ -10,7 +10,7 @@ if(NOT ENABLE_SHARED AND NOT ENABLE_STATIC)
   set(ENABLE_SHARED ON)
 endif()
 
-find_package(PkgConfig REQUIRED)
+find_package(PkgConfig)
 
 if(COMPILE_AS_CXX)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D__STDC_FORMAT_MACROS=1")
@@ -34,8 +34,10 @@ function(add_c_executable exec)
   add_executable(${exec} ${ARGN})
 endfunction()
 
-function(pkg_use_module mod)
-  pkg_search_module(${mod} ${ARGN})
+function(pkg_use_module mod pkg)
+  if(PKG_CONFIG_FOUND)
+    pkg_search_module(${mod} ${pkg})
+  endif()
   if(${mod}_FOUND)
     link_directories(${${mod}_LIBRARY_DIRS})
     include_directories(${${mod}_INCLUDE_DIRS})
diff --git a/toxcore/network.h b/toxcore/network.h
index e0122b5d..26126a22 100644
--- a/toxcore/network.h
+++ b/toxcore/network.h
@@ -24,6 +24,12 @@
 #ifndef NETWORK_H
 #define NETWORK_H
 
+#if defined(__GNUC__)
+#define GNU_EXTENSION __extension__
+#else
+#define GNU_EXTENSION
+#endif
+
 #ifdef PLAN9
 #include <u.h> // Plan 9 requires this is imported first
 // Comment line here to avoid reordering by source code formatters.
@@ -163,7 +169,7 @@ IP6;
 
 typedef struct {
     uint8_t family;
-    __extension__ union {
+    GNU_EXTENSION union {
         IP4 ip4;
         IP6 ip6;
     };