Clem, this reminds me: AIX on the mainframes and RS/6000 were different, weren't they? I only worked with the RS/6000 one. 

I suspect the Palo Alto people I talked to were getting stonewalled by the mainframe guys when it came to native channel programming. The mainframe VM folks probably thought of native AIX as an existential threat. 

Much as, ca. 2005, the Power hypervisor guys viewed native Linux as a threat -- they were certainly right in this case, many of us in the DOE labs wanted to get that hypervisor out of our lives. We spent some time at LANL trying to get native Linux from IBM but it was just a little too soon I guess. Funny how history repeats.