It's a beautiful story of nepotism and rent-seeking. Bill got the job from a powerful friend of his mother, bought someone else's work outright, customized it,

It's a beautiful story of nepotism and rent-seeking. Bill got the job from a powerful friend of his mother, bought someone else's work outright, customized it, and licensed it to IBM on incredibly Gates-friendly terms (pay per-unit, non-exclusive license). https://www.nytimes.com/1994/06/11/obituaries/mary-gates-64-helped-her-son-start-microsoft.html https://www.nytimes.com/1994/06/11/obituaries/mary-gates-64-... https://www.cnbc.com/2020/08/05/how-bill-gates-mother-influenced-the-success-of-microsoft.html https://www.cnbc.com/2020/08/05/how-bill-gates-mother-influe... > Mary was a respected businesswoman with many responsibilities, including her membership on the board of nonprofit organization United Way of King County. There, she met the late John Opel, then-chairman of IBM, who also was a member of the United Way board. > IBM's talks with Digital Research started to flounder, and when assessing options, Opel remembered Microsoft as the company "run by Bill Gates, Mary Gates' son," according to The Seattle Times. > When Microsoft won the job, it didn't actually have an operating system of its own. So in 1981, the company bought QDOS, an operating system created by hardware company Seattle Computer Products, and with it developed MS-DOS, the Microsoft Disk Operating System. Microsoft licensed its MS-DOS to IBM to use as the operating system for its personal computer. (In addition to Microsoft, IBM also contracted Digital Research and SofTech Microsystems to use their operating systems for IBM's personal computer.)