id Tech 4

id Tech 4, frequently known as the Doom 3 engine, is a computer game engine developed by id Software and first used in the PC game Doom 3. The engine was designed by John Carmack, who also created previous engines such as those for Doom and Quake, which are also generally recognized as marking significant advances in the field. The Doom 3 engine began as an enhancement to id Tech 3. Originally it was planned to be a complete rewrite of the engine's renderer, while still retaining other subsystems, such as file access, and memory management. After the new renderer was functional, however, the decision was made to switch from C to the C++ programming language, necessitating a complete restructuring and rewrite of the rest of the engine; today, while the Doom 3 engine contains code from id Tech 3, much of it has had to be rewritten. Like its predecessors, id Tech 4 will eventually be released as open source. At the QuakeCon 2007, John Carmack the lead graphics engine developer at id,... full article at wikipedia