It will run BSD for certain, I think I read that it will run a Linux as well.

Darwin would be interesting. The problem is that this is an old "PrEP" machine, and everyone had switched to "CHRP" by the time OS X was even a glint in Apple's eye. (aka: well before Apple bought NeXT.) So I really doubt anyone bothered to port Darwin to PrEP.

Yeah, a quick check shows that apparently Darwin only runs on G3 or newer on the PPC side.