Interested in ripping unencrypted DVDs? Linux-focused Arista Transcoder takes an approach worth noting:
One of the neat conversions that Arista Transcoder is able to do is to go straight from DVD to WebM, as well as iPod/iPhone/Android video formats! Here's a nice article on other video converters.
You can install Arista Transcoder via the command line on UbuntuLinux with this command:
sudo apt-get install arista