xine player
 

i can download clips off the internet and play it with xine. when i insert a dvd, click play, it says a xine engine plug-in needed.. why is it palying stuff off the internet and not my dvd. help

Well because some DVD's require certain "keys" and decription and stuff. You may want to check out Ogle to play DVD's, or mplayer. Once you have mplayer configured and it installs happily, it will play DVD's out of the box.

Ogle:
http://www.dtek.chalmers.se/groups/dvd/

That site will also have some of the software you will need to watch DVD's with Xine.