I had to pull the gopher server down (for now) to boot into OS X in order to run a QuakeWorld server. Not just any server, it's a "CoopWorld" server! Cooperative play is rare to find out there, it's mostly just death match.
Have a look...I personally play on an iBook G3, and it works great. The server is a PowerMac G4 tower.
quake.tauceti.org for info / port #