diff --git a/Aquaria/DSQ.cpp b/Aquaria/DSQ.cpp
index bc4fff4..ae5b482 100644
--- a/Aquaria/DSQ.cpp
+++ b/Aquaria/DSQ.cpp
@@ -153,7 +153,8 @@ Vector savesz;
 	#define APPNAME "Aquaria"
 #endif
 
-DSQ::DSQ(std::string fileSystem) : Core(fileSystem, LR_MAX, APPNAME, PARTICLE_AMOUNT_DEFAULT, "Aquaria")
+DSQ::DSQ(const std::string& fileSystem, const std::string& extraDataDir)
+: Core(fileSystem, extraDataDir, LR_MAX, APPNAME, PARTICLE_AMOUNT_DEFAULT, "Aquaria")
 {
 	// 2048
 	//createDirectory(getSaveDirectory());
diff --git a/Aquaria/DSQ.h b/Aquaria/DSQ.h
index 5043f36..258617e 100644
--- a/Aquaria/DSQ.h
+++ b/Aquaria/DSQ.h
@@ -1227,7 +1227,7 @@ enum NagType
 class DSQ : public Core
 {
 public:
-	DSQ(std::string fileSystem);
+	DSQ(const std::string& fileSystem, const std::string& extraDataDir);
 	~DSQ();
 
 	void init();
diff --git a/Aquaria/Main.cpp b/Aquaria/Main.cpp
index 215c659..290e54d 100644
--- a/Aquaria/Main.cpp
+++ b/Aquaria/Main.cpp
@@ -83,18 +83,31 @@ static void CheckConfig(void)
 	extern "C" int main(int argc,char *argv[])
 	{
 		std::string dsqParam = ""; // fileSystem
+		std::string extraDataDir = "";
 
+		const char *envPath = 0;
 #ifdef BBGE_BUILD_UNIX
-		const char *envPath = getenv("AQUARIA_DATA_PATH");
-		if (envPath != NULL)
+		envPath = getenv("AQUARIA_DATA_PATH");
+		if (envPath)
+		{
 			dsqParam = envPath;
+		}
 #endif
+#ifdef AQUARIA_DEFAULT_DATA_DIR
+		if(!envPath)
+			dsqParam = AQUARIA_DEFAULT_DATA_DIR;
+#endif
+#ifdef AQUARIA_EXTRA_DATA_DIR
+		if(!envPath)
+			extraDataDir = AQUARIA_EXTRA_DATA_DIR;
+#endif
+
 #endif
 
         CheckConfig();
 
         {
-            DSQ dsql(dsqParam);
+            DSQ dsql(dsqParam, extraDataDir);
             dsql.init();
             dsql.main();
             dsql.shutdown();
diff --git a/BBGE/Core.cpp b/BBGE/Core.cpp
index b71581c..5f865ce 100644
--- a/BBGE/Core.cpp
+++ b/BBGE/Core.cpp
@@ -41,6 +41,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
 #if BBGE_BUILD_WINDOWS
 #include <shlobj.h>
+#include <direct.h>
 #endif
 
 #ifdef BBGE_BUILD_SDL
@@ -884,12 +885,13 @@ static bool checkWritable(const std::string& path, bool warn, bool critical)
 
 
 const float SORT_DELAY = 10;
-Core::Core(const std::string &filesystem, int numRenderLayers, const std::string &appName, int particleSize, std::string userDataSubFolder)
+Core::Core(const std::string &filesystem, const std::string& extraDataDir, int numRenderLayers, const std::string &appName, int particleSize, std::string userDataSubFolder)
 : ActionMapper(), StateManager(), appName(appName)
 {
 	sound = NULL;
 	screenCapScale = Vector(1,1,1);
 	timeUpdateType = TIMEUPDATE_DYNAMIC;
+	_extraDataDir = extraDataDir;
 
 	fixedFPS = 60;
 
@@ -1093,6 +1095,13 @@ void Core::initPlatform(const std::string &filesystem)
 	}
 #endif
 #ifdef BBGE_BUILD_WINDOWS
+	if(filesystem.length())
+	{
+		if(_chdir(filesystem.c_str()) != 0)
+		{
+			debugLog("chdir failed: " + filesystem);
+		}
+	}
 	// FIXME: filesystem not handled
 #endif
 }
@@ -4858,6 +4867,9 @@ void Core::setupFileAccess()
 
 	//vfs.AddArchive("aqfiles.zip", false, "");
 
+	if(_extraDataDir.length())
+		vfs.MountExternalPath(_extraDataDir.c_str(), "", true, true);
+
 
 	debugLog("Done");
 #endif
diff --git a/BBGE/Core.h b/BBGE/Core.h
index 84b08cb..d0b0f0b 100644
--- a/BBGE/Core.h
+++ b/BBGE/Core.h
@@ -973,7 +973,7 @@ public:
 		NO_DESTROY
 	};
 	// init
-	Core(const std::string &filesystem, int numRenderLayers, const std::string &appName="BBGE", int particleSize=1024, std::string userDataSubFolder="");
+	Core(const std::string &filesystem, const std::string& extraDataDir, int numRenderLayers, const std::string &appName="BBGE", int particleSize=1024, std::string userDataSubFolder="");
 	void initPlatform(const std::string &filesystem);
 	~Core();
 
@@ -1402,6 +1402,7 @@ protected:
 	virtual void onRender(){}
 
 	void setupFileAccess();
+	std::string _extraDataDir;
 };
 
 extern Core *core;
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6c16bd0..552eb09 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -211,6 +211,19 @@ if (NOT(AQUARIA_CUSTOM_BUILD_ID STREQUAL ""))
   ADD_DEFINITIONS("-DAQUARIA_CUSTOM_BUILD_ID=\"${AQUARIA_CUSTOM_BUILD_ID}\"")
 endif (NOT(AQUARIA_CUSTOM_BUILD_ID STREQUAL ""))
 
+# Custom data directories
+SET(AQUARIA_DEFAULT_DATA_DIR "" CACHE STRING
+    "Default data directory (for package maintainers only)")
+if(NOT(AQUARIA_DEFAULT_DATA_DIR STREQUAL ""))
+    ADD_DEFINITIONS("-DAQUARIA_DEFAULT_DATA_DIR=\"${AQUARIA_DEFAULT_DATA_DIR}\"")
+endif(NOT(AQUARIA_DEFAULT_DATA_DIR STREQUAL ""))
+
+SET(AQUARIA_EXTRA_DATA_DIR "" CACHE STRING
+    "Extra data directory, overrides files from default datadir (for package maintainers only)")
+if(NOT(AQUARIA_EXTRA_DATA_DIR STREQUAL ""))
+    ADD_DEFINITIONS("-DAQUARIA_EXTRA_DATA_DIR=\"${AQUARIA_EXTRA_DATA_DIR}\"")
+endif(NOT(AQUARIA_EXTRA_DATA_DIR STREQUAL ""))
+
 # Aquaria/BBGE specific defines...
 
 ADD_DEFINITIONS(-DGL_GLEXT_LEGACY=1)