IIRC Unreal (the game) does work on Linux. Too bad UDK doesn't seem to work on Linux. OTOH I do have a dual boot machine with Win XP (though I haven't booted into windows in years now).....
From what I know, Ryan (icculus) Gordon is still working on it. But that might be my memory mixing that up with another game that took ages and I was not remotely interested in.
UnrealEd 3 is based on wxWindows and is theoretically portable to linux and MacOSX. When I was working there a few years back, however, it wasn't actively compiled on any platform other than Windows.
