In 1974, Gary Kildall revolutionized personal computing by creating CP/M, the first successful operating system. Despite early successes and significant revenue, DRI lost out to Microsoft when IBM chose to use a copy of CP/M, called PC DOS, in their PC due to cost. DRI continued to innovate but was eventually sold in 1991. Kildall’s legacy remains clouded by myths, including one involving Bill Gates and IBM. Despite this, his contributions to the microcomputer industry were celebrated posthumously. The Institute of Electrical and Electronic Engineering honored Kildall with a bronze IEEE Milestone for his foundational work in computing.
https://computerhistory.org/blog/fifty-years-of-the-personal-computer-operating-system/