Timothee 'TTimo' Besset from id Software confirmed officially that the next sequel of the Quake series, Quake IV will be released for the Linux platform.
The dedicated server will be released around the same time as the Windows version. The linux client, might be delayed a week or two. Quake4 will use the Simple Direct Media Layer (SDL) backend for input and OpenGL on Linux. The low level sys code for Linux had been needing a good rewrite for several years, so it made sense to use SDL now.

Quake 4 is the first game to utilize id Software's revolutionary DooM 3 technology. In the game, you are Matthew Kane, an elite member of Rhino Squad and Earth's valiant invasion force. Fight alone, with your squad, and in hover tanks and mechanized walkers as you engage in a heroic mission into the heart of the Strogg war machine. But, in this epic war between worlds, the only way to defeat the Strogg is to become one of them. Battle through early missions as a deadly marine, then after your capture as a marine-turned-Strogg with enhanced abilities and the power to turn the tide of the war.