Long ago the HP 3000 was faced with a problem at HP. The vendor wanted the system to fit in. Fit with customer expectations of compatibility. Fit into the ecosystem of open systems, those touted like HP-UX as uniform enough to accomodate many applications.
Stromasys applied itself to this issue to make the MPE/iX hardware more open. Charon takes a well-powered Intel server and gives it the ability to host the 3000's OS. Linux, such as Red Hat, is essential.
People outside of HP were thinking about this problem, too. Not long ago after we published a story about overlaying Red Hat onto MPE/iX, we examined possible ways to make a 3000 more Unix-ready. We referenced the HP MOST project, which invited customers to try a system that ran both HP-UX and MPE/iX. It wasn't the only concept HP scrapped without much of a field trial.
That Red Hat overlay onto MPE/iX from our article "is somewhat misleading jargon," according to Stan Sieler of Allegro. "HP could probably have made the Posix stuff cleaner—closer to say HP-UX." The Posix extensions that turned MPE XL into MPE/iX were licensed from MK Systems and were to have made the 3000 more compatible with open systems.
"HP also could have said, 'Let's junk our networking and grab the code from HP-UX with some changes,' " Sieler said. "That's particularly so because they'd been saying for years that the two systems had 'shared drivers.' "
I had proposed to HP managment (and key engineers) a different solution, albeit one that probably required more HP-UX-like networking support: Allow HP-UX binaries to be transparently run on MPE/iX.
Because of a key (but minor) difference in the ABI (Application Binary Interface) for the two platforms, you could fairly easily support running both kinds of binaries at the same time with relatively few changes. If I recall correctly, I received no response.