Something I've encountered only in my working career has been System P machines running AIX. Their not the easiest platform to develop, especially if you don't have local resources to learn upon. I earned my experience the hard way by attempting to resolve issues on production systems with just google searches, luck, and determination on my side. So with this in mind I'd like to share some links to resources that System P learners may find helpful.
Power Systems Community - lots of links here:
PSeriesTech - A System P support forum:
IBM Rational Cafe: