Urban Terror for Linux is a free multiplayer first person shooter developed by FrozenSand, that (thanks to the ioquake3-code) does not require Quake III Arena anymore.
It is available for Windows, Linux and Macintosh.
Urban Terror can be described as a Hollywood tactical shooter; somewhat realism based, but the motto is "fun over realism". This results in a very unique, enjoyable and addictive game.
Urban Terror started as a realism based "total conversion" mod for Quake III Arena.
Nowadays, Urban Terror is played using the free, stand-alone, ioquake3 engine modified, which doesn't require Quake III Arena, in addition to being an add-on to id Software's Quake III Arena.
Urban Terror is 100% free. It is a condition of the End User Licensing Agreement [EULA] when creating a mod that it not to be released for commercial retail. That means the team who created Urban Terror [Frozen Sand] is doing it for free.
If you purchased Urban Terror, then some unscrupulous individual may have ripped you off.
You should immediately report them to id Software or Frozen Sand.
Fonte : http://pkgs.org/ (16)