GZDoom is a port (a modification) of the original Doom source code, featuring:
- an OpenGL renderer, HQnX rescaling, 3D floor and model support
- Truecolor software rendering, extending the classic 8-bit palette
- a three-point projection software renderer, extending the classic
- Heretic, Hexen and Strife game modes and support for a lot of
- Boom and Hexen map extension support, scriptability with ACS and
ZScript, and various modding features regarding actors and scenery.
- Demo record/playback of classic and Boom demos is not supported.