The Quake 3 engine is open source. The Quake III: Arena game itself is not free. You must purchase the game (steam, gog) to use the data and play Quake 3 with ioquake3. If you do not want to do that you can play another game made with ioquake3.
You can download an ioquake3 test build for:
This Windows build is not code-signed and you may see a warning message from Windows smart screen similar to this one:
Windows protected your PC
Windows Defender SmartScreen prevented an unrecognized app from starting. Running this app might put your PC at risk.
That message can be safely ignored. We are working to resolve this issue. Please see this link for technical details.
macOS This is the main test build link, we also have extra builds from developer Tom Kidd:
- Legacy Universal 1 Build (PowerPC, intel 32 and 64bit)
- Universal 2 Build (Potentially Supporting M1 Macs, not tested. Fund an M1 Mac at this link so we can continue to support Apple’s platforms)
Modern versions of macOS may prevent these binaries from running because the apps are not notarized. You may see a warning from macOS that says:
ioquake3.app cannot be opened because the developer cannot be verified.
macOS cannot verify that this app is free from malware.
You may need to right-click (or hold down the ctrl/control key on the keyboard and click) to access a menu and select “Open” to open the app. We are working to resolve this issue. Please see this link for technical details.