He ripped off CPM to make DOS IIRC.
Yes, and then fooled Digital (VAX/VMS) who had a very tidy virtual memory swap method into partnering on Windows NT.
As soon as the rivals like OS/2 and the ever-elusive Linux desktop were out of the way, Digital was cast on the trash heap and Microsoft marched on its merry monopolistic way.
Bill is now in the fake-philanthopist business, and one can imagine how he’s treated his ‘partners’ as he goes about his exciting new life “vaccinating” people and buying up food production.