iRMX -- RiP
That little OS was years ahead of its time. Intel had a sort of CP/M it used it its MDS (development) systems but neither the system nor their emulators were up to the challenge of using the architecture of the 286 and beyond. iRMX filled the gap. Too bad that Intel did what they always seem to do with useful products -- they just dropped it.
I also had some contact with Microsoft's code in the early days thanks to their networking support in MS-DOS. The less said about MS-NET the better; my impression of Microsoft's programming capabilities was similar to that in the quote and I've not got more comfortable with their technologies in the intervening 30+ years. Still, software's like pop music -- there's no apparent correlation between ability to play and ability to make money, the key skill is 'showman' with talent being a useful, if secondary, capability.