BSPSource is a map decompiler for Source engine maps, written in Java. It decompiles .bsp map files back to .vmf files that can be loaded in Hammer, Valve's official level editor.

BSPSource is based on a reengineered version of VMEX 0.98g by Rof, which is no longer developed and lacks support for newer Source engine games.

• Support for more and newer Source engine games up to Dota 2.
• Support for new entity types:
  • func_areaportal
  • func_areaportalwindow
  • func_occluder
  • info_lighting
• Support for the tools/blocklight texture.
• Support for compressed and big-endian encoded maps (XBox 360, PS3)
• Decompiles VMEX maps flagged with protection and at least detects other anti-decompiling methods.
• Improved support for prop_static and info_overlay.
• Improved console output.
• New graphical user interface with output window.
• New command line interface.
• New integrated pakfile extractor.
• Numerous bug fixes.
• Open source.

• Some internal entities that are entirely consumed by vbsp can't be restored. This includes following entities:
  • func_instance
  • func_instance_parms
  • func_instance_origin
  • func_viscluster
  • info_no_dynamic_shadow
• Areaportal and occluder entities are somewhat difficult to decompile and sometimes have missing brushes or wrong textures.