Fedora?

Fedora uses the RPM package system, which isn't as good (or so I've heard) as Ubuntu's package system. The current released version (i.e., not a beta version) will obviously be the most stable version to run. Note though, that Fedora doesn't support mp3; instead they make extensive support available for OGG compression. In other words, Fedora doesn't come with any software that can play or convert mp3 files. The people at Fedora have some weird belief that mp3 has become too commercialised and, as a result, corrupt (in the moral sense rather than the file integrity sense).

Personally, I believe it's an exercise in futility to install any Linux based OS onto a Mac. Mac OS is built on BSD (which in turn is Unix based), and has Unix certification. What more security do you need? If you're really looking to use Linux, get an old PC from salvaged parts and install Ubuntu on that. Don't waste your Mac hardware on an operating system designed by and for hobbyist's and malcontents.

No offense at all, but seeing how you don't know what package manager/file type Fedora uses, I don't think you should go about trying to install it on a Mac. Unless you're doing it just for testing purposes or to mess around with.

Anyway, Fedora uses RPM (Red Hat Package Manager) since it's based on Red Hat. It's a bit more difficult to use than Ubuntu, but I think it's more powerful.