Game Groups > 3D Engine: id Tech 1

Games using the id Tech 1 graphics engine (formerly known as the "DOOM engine") (original or modified) by iD Software, Inc..

Doom's source code was released to the public on December 23, 1997 under a license allowing noncommercial use; in 1999, it was re-released under the GNU General Public License. This led to the development of numerous source ports adding new features to the engine.

Some facts:

• It was the first 3D game engine that allowed variable heights for floors and ceilings. However, it only allowed one floor or ceiling per area, making multi-storied levels impossible.
• John Carmack experimented with 16 bit textures, but found the overhead unacceptable for the game.