OpenArena is a community-produced deathmatch FPS based on GPL idTech3 technology. It is a freeware game application.
Here are some screenshots to illustrate the features and user interface of this application:
A free (gpl) PC games program for Windows. Screenshot of OpenArena - 1920px · 1080pxSingle-player or multi-player version of Quake III. Screenshot of OpenArena - 1920px · 1080pxOpenArena: User interface. Screenshot of OpenArena - 1920px · 1080pxScreenshot of OpenArena - Size: 1920px · 1080pxScreenshot of OpenArena - Size: 1920px · 1080pxScreenshot of OpenArena - Size: 1920px · 1080px