Most of the code comes from bpython/intern/opy_window.c, but two new functions were added, to access the file and image selector windows in Blender. * Added submodules Draw (gui) and BGL (OpenGL wrapper): The code comes from bpython/intern/opy_draw.c, with minor changes to integrate it in the new implementation. * Made changes to Camera, Lamp and Image submodules: The implementation was improved. These files should be good starting points for interested new coders to look at, now. * Renamed interface.[ch] to EXPP_interface.[ch] to avoid conflict: There is another interface.h file in source/blender/include.