Yeah, it might be kind of interesting to play around with IBM i/OS/400.
Oh, and I guess I shouldn't have called it a mainframe operating system; that's z/OS. IBM i is their minicomputer operating system.
Oh, and I guess I shouldn't have called it a mainframe operating system; that's z/OS. IBM i is their minicomputer operating system.
Sadly I never got to program into them, but at least .NET (on Windows), Android seem to share some of the ideas.