OpenArena is a community-produced death match FPS based on GPL idTech3 technology.
This game is one of the best multiplayer experience I had in FPS games. The high speed of movement and satisfactory weapons makes this game one of the best of its genre. Having multiple game modes like:
- Free for All
- Team Death match
- Tournament
- Capture the Flag
- Elimination
- CTF Elimination
- Last Man Standing
- Domination
OpenArena Team, GPL, via Wikimedia Commons
You should really try this game.
Download it right here!