Red Hat Magazine published an article about installing Fedora Core 4 on the Mac mini

The Apple Mac mini is Apple's latest offer in the arena of groovy computing. It also serves a Linux geek's bliss: it sports an affordable PowerPC system in a small, quiet, stackable, and attractive case.

Models available from Apple currently ship either with the 1.25GHz or 1.42GHz PowerPC G4 processor and with 40GB or 80GB of disk space by default. It comes with a Radeon 9200 32MB video card and a standard of 256MB of RAM (which can be upgraded). Options for Bluetooth and Airport Extreme exist, however the latter will not work on Linux. Note that it only has one memory slot, so upgrading the memory is recommended at purchase time.

Installing Fedora Core on the Mac mini