Sounds like installing Q4 on your linux box might not be all it's cracked up to be. Joe Barr over at Linux.com was certainly less than enamoured with his installation experience...

"As soon as I read the news on Slashdot that id Software's just released Quake 4 was already available as both a Linux client and game server, I ran out and dropped $50 for the game. The box contained 4 CDs, a game guide, and a license key. But that's not enough to let you play Quake 4 on Linux."