I installed MacOS 9 over the weekend on my PowerWave. It seemed pretty useable, but amazingly similar to Windows
/ducks
I'm trying to install Fedora Core 4 PPC on it at the moment
I would def consider a nice more generic PPC OS, rather than Mac OS. There are 15 linux distros available for PPC (according to linux.org), including SuSE, YDL, Mandrake, Gentoo, Debian... they should run nicely on a G3