IMHO Its a good thing that Linux is available for different kinds of hardware. And if I do remember correct did Linux dist's for PPC exist before OSX was public available.

Mac is not a bad platform to run *nix on, if you will get around some issues. "I had problems a few years ago but it's probably easier install today. When I got the system properly installed it runned like a dream. I did use it to run a squid proxy on a PPC with Linux for more then a year ("36 multimedia students used the proxy"), I had no real issues with that machine it just kept on running .

IMO Linux on a PPC is far more powerful then MacOS 9 and MacOSX Server 1.0 (it was the last version I have used, I dont use Mac today).

~micael