The GZDoom FAQ

Q: What is GZDoom?

A: GZDoom is a Doom source port based on ZDoom. It features an OpenGL renderer and lots of new features, among them:
  • 3D floors
  • Dynamic lights
  • Quake2/Unreal style skyboxes
  • True color texture support
  • Model support (limited at the moment)
It also contains many bug fixes not present in the most recent ZDoom versions.

Q: What version of ZDoom is GZDoom based on?

It was originally based on the 2.0.96x community build but it has integrated all new features and bug fixes from 2.0.98.

Q: I can't use or don't like OpenGL rendering. Is this still worth the download?

Sure. GZDoom still contains the complete software renderer. The only limitations are that you can't use 3D floors, dynamic lights, Q2 style skyboxes and True color textures. In effect you get ZDoom with all the bug fixes and non-renderer specific new features. That includes complete .96x DECORATE support including inventory items and weapons.

Q: I want to create levels with custom DECORATE inventory items and weapons. Regular ZDoom still doesn't support them. Am I in danger of losing potential players because they can't or won't run OpenGL?

No. As long as you don't use any GL-specific features your WAD will run perfectly with GZDoom's software renderer and since that is the same as ZDoom's it should run on any system that supports ZDoom. As of version 0.9.28 it is possible to disable the entire OpenGL subsystem in the menu so that the engine behaves as if it wasn't there at all.