So for my project i'm trying to pull data from the university database and pop it into some sort of caldav compliant calendar server which students can use to access their timetables easier than the dreaded ISS system.

Turns out Apple made one (Calendar Server) and it's bastardly hard to make it work on Linux (it's freely available if you're an absolute expert) so i've gone ahead and bought OSX Server 10.5. As far as i'm aware that's the one that has Calendar Server in and also runs on a PPC (Powermac G5) processor!

What i'm wondering is... Can this be used like a normal version of OSX? Like... would it be fine if I just wiped my installation of Leopard and put this on as a replacement?

Yes, the server version isn't *that* different from the client edition of OS X, just with extra components bolted on. It's a bit more advanced than that, but it will work on just about any Mac that is capable of running the equivalent client edition.

Some people use it instead of "normal" OSX as it's supposedly much faster. It certainly seems to run very fast on my Quicksilver G4.