The Source engine is a 3D game engine developed by Valve Corporation. Its unique features include a large degree of modularity and flexibility, an artist-driven, shader-based renderer, accurate lip sync and facial expression technology, and a powerful, efficient and completely network-enabled physics system.
A simple tool used to decompile .bmp files (compiled valve map files). You can decompile any Valve game's maps. after vmeX turns them into a .vmf you can edit them in programs such as hammer.