I have a couple of music files in Ogg Vorbis format, a format that iTunes does not support by default.
Before, I used the Ogg Vorbis QuickTime 6.2 component written by Jordan Mendelson. Notice, however, the “6” in that title. Mac OS X 10.4 “Tiger” uses QuickTime 7. If you come to a Ogg Vorbis song file in your iTunes playlist on 10.4 when you have Jordan’s component installed, iTunes crashes.
Even cooler than that, the above page is really a bit of a developer Weblog, describing some of the steps he’s taken to make the component. If he got himself an RSS feed, I’d subscribe. He even has a teaser: “Watch this space.” Guess Apple isn’t the only one keeping secrets, eh?