diff --git a/Makefile.src.in b/Makefile.src.in
index 739a9aa3bc..e0083ce2a6 100644
--- a/Makefile.src.in
+++ b/Makefile.src.in
@@ -278,8 +278,8 @@ $(ENDIAN_CHECK): $(SRC_DIR)/endian_check.cpp
 $(SRC_DIR)/rev.cpp: $(CONFIG_CACHE_VERSION) $(SRC_DIR)/rev.cpp.in
 	$(Q)cat $(SRC_DIR)/rev.cpp.in      | sed "s@\!\!REVISION\!\!@$(REV_NR)@g;s@!!VERSION!!@$(REV)@g;s@!!MODIFIED!!@$(MODIFIED)@g;s@!!DATE!!@`date +%d.%m.%y`@g" > $(SRC_DIR)/rev.cpp
 
-$(SRC_DIR)/ottdres.rc: $(CONFIG_CACHE_VERSION) $(SRC_DIR)/ottdres.rc.in
-	$(Q)cat $(SRC_DIR)/ottdres.rc.in | sed "s@\!\!REVISION\!\!@$(REV_NR)@g;s@!!VERSION!!@$(REV)@g;s@!!DATE!!@`date +%d.%m.%y`@g" > $(SRC_DIR)/ottdres.rc
+$(SRC_DIR)/os/windows/ottdres.rc: $(CONFIG_CACHE_VERSION) $(SRC_DIR)/os/windows/ottdres.rc.in
+	$(Q)cat $(SRC_DIR)/os/windows/ottdres.rc.in | sed "s@\!\!REVISION\!\!@$(REV_NR)@g;s@!!VERSION!!@$(REV)@g;s@!!DATE!!@`date +%d.%m.%y`@g" > $(SRC_DIR)/os/windows/ottdres.rc
 
 FORCE:
 
@@ -290,7 +290,7 @@ clean:
 	$(Q)rm -f $(DEPS) $(OBJS) $(TTD) $(DEPEND) $(TTD:%=$(BIN_DIR)/%) $(CONFIG_CACHE_COMPILER) $(CONFIG_CACHE_LINKER) $(CONFIG_CACHE_ENDIAN) $(CONFIG_CACHE_SOURCE) $(ENDIAN_TARGETS)
 
 mrproper: clean
-	$(Q)rm -f $(SRC_DIR)/rev.cpp $(SRC_DIR)/ottdres.rc
+	$(Q)rm -f $(SRC_DIR)/rev.cpp $(SRC_DIR)/os/windows/ottdres.rc
 
 %.o:
 	@echo '$(STAGE) No such source-file: $(@:%.o=%).[c|cpp|mm|rc]'
diff --git a/os/win32/installer/build_installers.bat b/os/windows/installer/build_installers.bat
similarity index 100%
rename from os/win32/installer/build_installers.bat
rename to os/windows/installer/build_installers.bat
diff --git a/os/win32/installer/cdfinder.ini b/os/windows/installer/cdfinder.ini
similarity index 100%
rename from os/win32/installer/cdfinder.ini
rename to os/windows/installer/cdfinder.ini
diff --git a/os/win32/installer/install.nsi b/os/windows/installer/install.nsi
similarity index 100%
rename from os/win32/installer/install.nsi
rename to os/windows/installer/install.nsi
diff --git a/os/win32/installer/top.bmp b/os/windows/installer/top.bmp
similarity index 100%
rename from os/win32/installer/top.bmp
rename to os/windows/installer/top.bmp
diff --git a/os/win32/installer/version_win32.txt b/os/windows/installer/version_win32.txt
similarity index 100%
rename from os/win32/installer/version_win32.txt
rename to os/windows/installer/version_win32.txt
diff --git a/os/win32/installer/version_win64.txt b/os/windows/installer/version_win64.txt
similarity index 100%
rename from os/win32/installer/version_win64.txt
rename to os/windows/installer/version_win64.txt
diff --git a/os/win32/installer/version_win9x.txt b/os/windows/installer/version_win9x.txt
similarity index 100%
rename from os/win32/installer/version_win9x.txt
rename to os/windows/installer/version_win9x.txt
diff --git a/os/win32/installer/welcome.bmp b/os/windows/installer/welcome.bmp
similarity index 100%
rename from os/win32/installer/welcome.bmp
rename to os/windows/installer/welcome.bmp
diff --git a/projects/determineversion.vbs b/projects/determineversion.vbs
index 7104b833a1..1c6f48552d 100755
--- a/projects/determineversion.vbs
+++ b/projects/determineversion.vbs
@@ -44,7 +44,7 @@ Sub UpdateFiles(version)
 	End If
 
 	UpdateFile modified, revision, version, cur_date, "../src/rev.cpp"
-	UpdateFile modified, revision, version, cur_date, "../src/ottdres.rc"
+	UpdateFile modified, revision, version, cur_date, "../src/os/windows/ottdres.rc"
 End Sub
 
 Function ReadRegistryKey(shive, subkey, valuename, architecture)
@@ -286,6 +286,6 @@ End Function
 
 Dim version
 version = DetermineSVNVersion
-If Not (IsCachedVersion(version) And CheckFile("../src/rev.cpp") And CheckFile("../src/ottdres.rc")) Then
+If Not (IsCachedVersion(version) And CheckFile("../src/rev.cpp") And CheckFile("../src/os/windows/ottdres.rc")) Then
 	UpdateFiles version
 End If
diff --git a/projects/openttd_vs80.vcproj b/projects/openttd_vs80.vcproj
index 9e868d5f67..566353e7bb 100644
--- a/projects/openttd_vs80.vcproj
+++ b/projects/openttd_vs80.vcproj
@@ -16,7 +16,7 @@
 	</Platforms>
 	<ToolFiles>
 		<ToolFile
-			RelativePath="..\src\masm64.rules"
+			RelativePath="..\src\os\windows\masm64.rules"
 		/>
 	</ToolFiles>
 	<Configurations>
@@ -652,7 +652,7 @@
 				>
 			</File>
 			<File
-				RelativePath=".\..\src\ottdres.rc"
+				RelativePath=".\..\src\os\windows\ottdres.rc"
 				>
 			</File>
 			<File
@@ -764,7 +764,7 @@
 				>
 			</File>
 			<File
-				RelativePath=".\..\src\win32.cpp"
+				RelativePath=".\..\src\os\windows\win32.cpp"
 				>
 			</File>
 			<File
@@ -1624,7 +1624,7 @@
 				>
 			</File>
 			<File
-				RelativePath=".\..\src\win32.h"
+				RelativePath=".\..\src\os\windows\win32.h"
 				>
 			</File>
 			<File
@@ -3585,7 +3585,7 @@
 			Filter="asm"
 			>
 			<File
-				RelativePath=".\..\src\win64.asm"
+				RelativePath=".\..\src\os\windows\win64.asm"
 				>
 				<FileConfiguration
 					Name="Release|Win32"
diff --git a/projects/openttd_vs80.vcproj.in b/projects/openttd_vs80.vcproj.in
index 80f3631109..566dc0c3e9 100644
--- a/projects/openttd_vs80.vcproj.in
+++ b/projects/openttd_vs80.vcproj.in
@@ -16,7 +16,7 @@
 	</Platforms>
 	<ToolFiles>
 		<ToolFile
-			RelativePath="..\src\masm64.rules"
+			RelativePath="..\src\os\windows\masm64.rules"
 		/>
 	</ToolFiles>
 	<Configurations>
@@ -458,7 +458,7 @@
 			Filter="asm"
 			>
 			<File
-				RelativePath=".\..\src\win64.asm"
+				RelativePath=".\..\src\os\windows\win64.asm"
 				>
 				<FileConfiguration
 					Name="Release|Win32"
diff --git a/projects/openttd_vs90.vcproj b/projects/openttd_vs90.vcproj
index b74e04810e..310bc574ee 100644
--- a/projects/openttd_vs90.vcproj
+++ b/projects/openttd_vs90.vcproj
@@ -17,7 +17,7 @@
 	</Platforms>
 	<ToolFiles>
 		<ToolFile
-			RelativePath="..\src\masm64.rules"
+			RelativePath="..\src\os\windows\masm64.rules"
 		/>
 	</ToolFiles>
 	<Configurations>
@@ -649,7 +649,7 @@
 				>
 			</File>
 			<File
-				RelativePath=".\..\src\ottdres.rc"
+				RelativePath=".\..\src\os\windows\ottdres.rc"
 				>
 			</File>
 			<File
@@ -761,7 +761,7 @@
 				>
 			</File>
 			<File
-				RelativePath=".\..\src\win32.cpp"
+				RelativePath=".\..\src\os\windows\win32.cpp"
 				>
 			</File>
 			<File
@@ -1621,7 +1621,7 @@
 				>
 			</File>
 			<File
-				RelativePath=".\..\src\win32.h"
+				RelativePath=".\..\src\os\windows\win32.h"
 				>
 			</File>
 			<File
@@ -3582,7 +3582,7 @@
 			Filter="asm"
 			>
 			<File
-				RelativePath=".\..\src\win64.asm"
+				RelativePath=".\..\src\os\windows\win64.asm"
 				>
 				<FileConfiguration
 					Name="Release|Win32"
diff --git a/projects/openttd_vs90.vcproj.in b/projects/openttd_vs90.vcproj.in
index bc47bbd9fa..d4f3214b1b 100644
--- a/projects/openttd_vs90.vcproj.in
+++ b/projects/openttd_vs90.vcproj.in
@@ -17,7 +17,7 @@
 	</Platforms>
 	<ToolFiles>
 		<ToolFile
-			RelativePath="..\src\masm64.rules"
+			RelativePath="..\src\os\windows\masm64.rules"
 		/>
 	</ToolFiles>
 	<Configurations>
@@ -455,7 +455,7 @@
 			Filter="asm"
 			>
 			<File
-				RelativePath=".\..\src\win64.asm"
+				RelativePath=".\..\src\os\windows\win64.asm"
 				>
 				<FileConfiguration
 					Name="Release|Win32"
diff --git a/source.list b/source.list
index 21c6d556b7..03186c07d4 100644
--- a/source.list
+++ b/source.list
@@ -49,10 +49,10 @@ npf.cpp
 openttd.cpp
 os_timer.cpp
 #if WIN32
-	ottdres.rc
+	os/windows/ottdres.rc
 #end
 #if WINCE
-	ottdres.rc
+	os/windows/ottdres.rc
 #end
 pathfind.cpp
 pbs.cpp
@@ -97,12 +97,12 @@ tile_map.cpp
 #if WIN32
 #else
 	#if WINCE
-		win32.cpp
+		os/windows/win32.cpp
 	#else
 		#if OS2
-			os2.cpp
+			os/os2/os2.cpp
 		#else
-			unix.cpp
+			os/unix/unix.cpp
 		#end
 	#end
 #end
@@ -112,7 +112,7 @@ viewport.cpp
 waypoint.cpp
 widget.cpp
 #if WIN32
-	win32.cpp
+	os/windows/win32.cpp
 #end
 window.cpp
 
@@ -334,7 +334,7 @@ water.h
 waypoint_base.h
 waypoint_func.h
 widget_type.h
-win32.h
+os/windows/win32.h
 music/win32_m.h
 sound/win32_s.h
 video/win32_v.h
diff --git a/src/fontcache.cpp b/src/fontcache.cpp
index 8dd4f5c970..4116705c0c 100644
--- a/src/fontcache.cpp
+++ b/src/fontcache.cpp
@@ -51,7 +51,7 @@ enum {
 #ifdef WIN32
 #include <windows.h>
 #include <shlobj.h> /* SHGetFolderPath */
-#include "win32.h"
+#include "os/windows/win32.h"
 
 /**
  * Get the short DOS 8.3 format for paths.
diff --git a/src/music/dmusic.cpp b/src/music/dmusic.cpp
index 5042571ad5..988884b8f3 100644
--- a/src/music/dmusic.cpp
+++ b/src/music/dmusic.cpp
@@ -16,7 +16,7 @@
 	#undef WIN32_LEAN_AND_MEAN // Don't exclude rarely-used stuff from Windows headers
 #endif
 #include "../debug.h"
-#include "../win32.h"
+#include "../os/windows/win32.h"
 #include "dmusic.h"
 
 #include <windows.h>
diff --git a/src/os2.cpp b/src/os/os2/os2.cpp
similarity index 94%
rename from src/os2.cpp
rename to src/os/os2/os2.cpp
index a40a46c844..06508b3618 100644
--- a/src/os2.cpp
+++ b/src/os/os2/os2.cpp
@@ -9,16 +9,16 @@
 
 /** @file os2.cpp OS2 related OS support. */
 
-#include "stdafx.h"
-#include "openttd.h"
-#include "variables.h"
-#include "gui.h"
-#include "fileio_func.h"
-#include "fios.h"
-#include "functions.h"
-#include "core/random_func.hpp"
-#include "string_func.h"
-#include "textbuf_gui.h"
+#include "../../stdafx.h"
+#include "../../openttd.h"
+#include "../../variables.h"
+#include "../../gui.h"
+#include "../../fileio_func.h"
+#include "../../fios.h"
+#include "../../functions.h"
+#include "../../core/random_func.hpp"
+#include "../../string_func.h"
+#include "../../textbuf_gui.h"
 
 #include "table/strings.h"
 
diff --git a/src/unix.cpp b/src/os/unix/unix.cpp
similarity index 97%
rename from src/unix.cpp
rename to src/os/unix/unix.cpp
index dc55a3a37a..bbe916c57f 100644
--- a/src/unix.cpp
+++ b/src/os/unix/unix.cpp
@@ -9,12 +9,12 @@
 
 /** @file unix.cpp Implementation of Unix specific file handling. */
 
-#include "stdafx.h"
-#include "openttd.h"
-#include "variables.h"
-#include "textbuf_gui.h"
-#include "functions.h"
-#include "core/random_func.hpp"
+#include "../../stdafx.h"
+#include "../../openttd.h"
+#include "../../variables.h"
+#include "../../textbuf_gui.h"
+#include "../../functions.h"
+#include "../../core/random_func.hpp"
 
 #include "table/strings.h"
 
@@ -117,8 +117,8 @@ bool FiosIsHiddenFile(const struct dirent *ent)
 
 #include <iconv.h>
 #include <errno.h>
-#include "debug.h"
-#include "string_func.h"
+#include "../../debug.h"
+#include "../../string_func.h"
 
 const char *GetCurrentLocale(const char *param);
 
diff --git a/src/masm64.rules b/src/os/windows/masm64.rules
similarity index 100%
rename from src/masm64.rules
rename to src/os/windows/masm64.rules
diff --git a/src/ottdres.rc.in b/src/os/windows/ottdres.rc.in
similarity index 100%
rename from src/ottdres.rc.in
rename to src/os/windows/ottdres.rc.in
diff --git a/src/win32.cpp b/src/os/windows/win32.cpp
similarity index 98%
rename from src/win32.cpp
rename to src/os/windows/win32.cpp
index d262abebdd..432755fbe4 100644
--- a/src/win32.cpp
+++ b/src/os/windows/win32.cpp
@@ -9,35 +9,35 @@
 
 /** @file win32.cpp Implementation of MS Windows system calls */
 
-#include "stdafx.h"
-#include "openttd.h"
-#include "debug.h"
-#include "saveload/saveload.h"
-#include "gfx_func.h"
-#include "textbuf_gui.h"
-#include "fileio_func.h"
-#include "fios.h"
-#include "rev.h"
+#include "../../stdafx.h"
+#include "../../openttd.h"
+#include "../../debug.h"
+#include "../../saveload/saveload.h"
+#include "../../gfx_func.h"
+#include "../../textbuf_gui.h"
+#include "../../fileio_func.h"
+#include "../../fios.h"
+#include "../../rev.h"
 #include <windows.h>
 #include <winnt.h>
 #include <wininet.h>
 #include <fcntl.h>
 #include <shlobj.h> /* SHGetFolderPath */
-#include "variables.h"
+#include "../../variables.h"
 #include "win32.h"
-#include "core/alloc_func.hpp"
-#include "functions.h"
-#include "core/random_func.hpp"
-#include "core/bitmath_func.hpp"
-#include "string_func.h"
-#include "gamelog.h"
+#include "../../core/alloc_func.hpp"
+#include "../../functions.h"
+#include "../../core/random_func.hpp"
+#include "../../core/bitmath_func.hpp"
+#include "../../string_func.h"
+#include "../../gamelog.h"
 #include <ctype.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #if defined(_MSC_VER) && !defined(WINCE)
 	#include <dbghelp.h>
-	#include "strings_func.h"
+	#include "../../strings_func.h"
 #endif
 
 static bool _has_console;
diff --git a/src/win32.h b/src/os/windows/win32.h
similarity index 100%
rename from src/win32.h
rename to src/os/windows/win32.h
diff --git a/src/win64.asm b/src/os/windows/win64.asm
similarity index 100%
rename from src/win64.asm
rename to src/os/windows/win64.asm
diff --git a/src/video/win32_v.cpp b/src/video/win32_v.cpp
index fffb867708..efa4295edc 100644
--- a/src/video/win32_v.cpp
+++ b/src/video/win32_v.cpp
@@ -13,7 +13,7 @@
 #include "../openttd.h"
 #include "../gfx_func.h"
 #include "../variables.h"
-#include "../win32.h"
+#include "../os/windows/win32.h"
 #include "../rev.h"
 #include "../blitter/factory.hpp"
 #include "../network/network.h"