If you are running Ubuntu Hardy Heron (8.04) it should be pretty straight forward. I made up a
Linux install script that's attached to the wiki page. In order to run the client, you'll also need
Python-Ogre installed, but that should be easy if you just follow the instructions in
this thread. Installing on Debian or earlier Ubuntu releases shouldn't be too tricky, but for other Linux distros, you may have to compile Python-Ogre yourself. That's not an easy task-- at least in my past experiences, it may have improved since I last tried. I will admit that I haven't run the client much on Linux recently, so it's possible there are bugs. You will definitely have to update the plugins.cfg file to reflect where Python-Ogre's plugin .so's are installed. Definitely let me know if you hit a snag and I'm sure I can help.
FYI, both of the MV3D servers that are up are running on Linux.
Good luck!
Thanks,
Mike