Since you did not state for which OS version, you might just want to try looking around on this site
http://www.versiontracker.com/macosx/topsearches/dvd
http://www.wormintheapple.gr/macdvd/links.html
http://www.wormintheapple.gr/macdvd/mtr.html
http://www.mrfreefree.com/free/mac/10/