Obozrenie is a game server browser for Linux that can be used to access information about and connect to multiplayer servers.
4 Nov 2006)
XQF is a game server browser and launcher for Unix/X11 for many popular games such as the Quake series, Unreal Tournament series, Half-Life etc.
29 Jun 2009)
All-Knowing Mind is a game server browser for first person shooter games written in Java.