It is a strange turn of events that DRI did not supply the dominant OS for the IBM PC. Before watching this I didn't know that CP/M-86 went for $240 and PC-DOS for $40. Gates' shrewdness (I'll call it that) enabled him to control the PC (as in IBM PCs and clones) market. Sounds like Kildall was a great guy and a genius, who did not win in the "business is war" competition. I remember working at Egghead Software and GEM being superior to the Windows of the day, but it never took off. Xerox (who should have owned GUI computing) made Ventura Publisher based on GEM. Now Gates wants to be seen as a kindly benefactor to us all.....
Looking into this more, I see that Lotus 1-2-3 is considered to have greatly helped the IBM PC become dominant, and it did not run on CP/M-86 (i would be interested in any confirmation or rebuttal of this though). So Microsoft's success was partially due to Lotus as well as IBM, both of whom they would defeat in PC OSes and spreadsheets. There was rumored to be a saying at MS "DOS isn't done until Lotus won't run".....And Mitch Kapor ended up promoting free software (was head of Mozilla) and tech inclusion with his foundation.
Arguably the man who made Bill Gates. Gary Kildall was founder of Digital Research, makers of CP/M the first operating system for personal computers.