alt Hacker NewsThat’s odd, because I remember being a user of MUSIC on the university System/360. I imagine it also sounds odd to all those people who ran AT&T Unix on their PDP/11 systems instead of a Digital OS like RTS/11. Or the people who ran Xenix on their PCs. Or the folks like me who installed OS/2 on what was sold as an MS-DOS machine. Then there were the folks who ran A+ on their Atari.
Oh yeah, odd. Anyway, I’m aware of alternate mainframe OSs but I’m not sure how common using one was. Other than OS2, alternate OSs for other systems were rather rare, though it is worth noting that they were not forbidden or blocked.