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.Source supports both 32-bit and 64-bit environments and the Microsoft Windows, Xbox, Xbox 360, and PlayStation 3 platforms (the last being launched with The Orange Box). It debuted in October 2004 with Counter-Strike: Source and Half-Life 2.