Linux can play realplayer. You can install realplayer using: klik.berlios.de

I use kaffeine and mplayer. Add this to you apt sources.lst:
deb ftp://ftp.nerim.net/debian-marillat/ unstable main

Then in root konsole:
apt-get update
apt-get mplayer-686(**depends on your system) mplayer-fonts w32codecs kaffeine