storma: I've got it running under linux. :) The steps I took are..
1. Installed using Playonlinux or wine, whatever you fancy.
2. Grab the linux patch from here:
http://www.fileplanet.com/141074/140000/fileinfo/Unreal-Tournament-2004-Patch-v3369-[Linux]-
3. extract the patch then cp -r UT2004-Patch/* /path/to/GOG.com/Unreal Tournament 2004/
4. cp libSDL-1.2.so.0 to the System dir within GOG.com/Unreal Tournament 2004/
5. cp libopenalpp.so.1.0.0 to System/openal.so
6. from wine open up regedit and navigate to HKEY_LOCAL_MACHINE -> Software -> Unreal Technology -> Installed Apps -> UT2004. There you will find a CDKey. cp that value to System/CDkey
7. Finally all you have to do is run ut2004-bin from the system dir.
Hi. I did everything from your how to and it works.... almost :(
I can run game, but menu is unreadable and game run game but it runs very slowly.
Cheers.