Serious Sam is an (old) first person shooter. See http://en.wikipedia.org/wiki/Serious_sam
Because it's quite old, it's low on system resources, it will even play on an old laptop.
Get the program from ftp://serious:email@example.com/ (This seems not to work at the moment)
Or alternatively, get it from using DC Plus, Serious Sam directory.
Read the readme.txt, how to set it up.
A Serious Sam server is running 24/7 normally at 10.15.144.2:25600
The server is running co-op mode during the week. This means anyone can start playing without having to wait for other players to come in.
I intend to run the server in combat mode on Wednesdays from 20:00 onwards. All welcome!
Questions? Contact Wcool