Xonotic (2011)

Release:
Developer: Team Xonotic
Xonotic is an addictive, arena-style first person shooter with crisp movement and a wide array of weapons. It combines intuitive mechanics with in-your-face action to elevate your heart rate. Xonotic is and will always be free-to-play. It is available under the copyleft-style GPLv3+ license.
Platforms: Linux, Mac, PC (Microsoft Windows)
Genres: Shooter