Q3knockOut changes your Quake experience in a very unique way: Scoring is not done by directly hit and kill your enemy, but by pushing him out of the area into the void or other deadly spots in a map like lava and such.

This mod only works for open-space ("floater") maps, like featured here:
http://lvlworld.com/topmaps/5/12
There is a 6-slot Q3A server running Q3knockOut (serverside-only mod, no install needed to connect and play on that server!):
194.97.165.140:27960
The name of this server is: "Q3knockOut @4Netplayers"
Homepage:
http://www.moddb.com/mods/q3knockout/