What Is ioquake3?

ioquake3 is a free and open-source first-person shooter engine built from the Quake 3: Arena and Quake 3: Team Arena source code. It is licensed under GPL version 2 and was first released under that license by id software on August 20, 2005. Since then, a dedicated volunteer team has maintained it, fixing bugs and adding features to improve the engine. ioquake3 is a community project — it is not part of, or sponsored by, id software, Bethesda, or Microsoft.

What ioquake3 actually is

ioquake3 is an engine, not a game. The engine is the software layer that handles rendering, input, networking, audio, and the core systems a first-person shooter runs on. The game content — maps, models, sounds, and gameplay logic — comes from Quake 3: Arena, Quake 3: Team Arena, or community-made mods.

That distinction matters because it explains what you can and cannot do with ioquake3 out of the box:

• You can use ioquake3 to play Quake 3: Arena, Quake 3: Team Arena, and the mods people have made for those games.
• You can use it to run your own game server.
• You can build your own game from the source code, which is hosted in git on GitHub.
• You can play games that other teams have built using ioquake3 if you don't already own Quake 3.

Where it came from

id software released the Quake 3: Arena and Team Arena source code under the GPL v2 on August 20, 2005. ioquake3 was first released under that same license. The project has been maintained continuously since then by volunteers, with the goal of keeping the engine working on modern systems and improving it beyond its original state.

What you can do with it

Who maintains it and how to get involved

ioquake3 is maintained by a volunteer team and supported by resources from Discourse.org, icculus.org, and Nuclear Monster. If you want to give back, the project lists ways to contribute, and you can follow updates on Mastodon and Blue Sky.

Downloads and platforms

ioquake3 provides downloads for Windows, macOS, and Linux, with additional downloads available through the project's download page. If you want to buy Quake 3: Arena and Team Arena, the site links to a purchase page.

The short version

ioquake3 is the community-maintained, GPL v2 open-source engine derived from Quake 3: Arena and Team Arena. It lets you play those games and their mods, run servers, or build something new from the source — but it is an independent community project, not an official id software, Bethesda, or Microsoft product.