The original Quake 2 sources as originally released under the GPL license on December 21, 2001.

null/glimp_null.c

@@ -0,0 +1,34 @@
+#include "../ref_gl/gl_local.h"
+
+void		GLimp_BeginFrame( float camera_separation )
+{
+}
+
+void		GLimp_EndFrame( void )
+{
+}
+
+int 		GLimp_Init( void *hinstance, void *hWnd )
+{
+}
+
+void		GLimp_Shutdown( void )
+{
+}
+
+int     	GLimp_SetMode( int *pwidth, int *pheight, int mode, qboolean fullscreen )
+{
+}
+
+void		GLimp_AppActivate( qboolean active )
+{
+}
+
+void		GLimp_EnableLogging( qboolean enable )
+{
+}
+
+void		GLimp_LogNewFrame( void )
+{
+}
+