ioquake3 (or ioq3 for short) is a fork of the Id Tech 3 engine (that is the base of Quake III Arena), and is released under the free GPLv2 license.

After the source code of Quake III Arena has been released by id Software, programmers have been able to improve it and use it for their own games. The ioq3 team corrected many bugs and security issues and also adds features to the original engine while maintaining compatibility.

ioquake3 allows two major things:

  • It can be used in place of the original Quake 3 engine executable. You still need a copy of Quake 3, because models and maps are still under the copyright of id Software. ioquake3 only consists of the engine, not game assets.
    "Data installer download" from their site runs a "wizard" that will ask for your Quake3 (and optionally Team Arena) CD (to get pak0.pk3 file) and already contains the additional pk3 files from Q3 1.32 PointRelease.
  • It can be used to create "standalone" versions from games that were formerly requiring a copy of Quake 3 (i.e. running as a mod under Quake 3). This allowed the creation of OpenArena and other games that use ioq3. Standalone games that do not require compatibility with id Tech 3 can also benefit from further improvements in the ioquake3 engine.

Official OpenArena engine is a fork of ioquake3. It's no longer synchronized with it. Using ioquake3 engine with OpenArena may cause unwanted results.

Derived games

Some projects which use the ioquake3 engine:

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