Gary Arlen Kildall (May 19, 1942 – July 11, 1994) was an American computer scientist and microcomputer entrepreneur who created the CP/M operating system and founded Digital Research, Inc. (DRI). Kildall was one of the first people to see microprocessors as fully capable computers rather than equipment controllers and to organize a company around this concept. He also co-hosted the PBS TV show The Computer Chronicles. Although his career in computing spanned more than two decades, he is mainly remembered in connection with IBM's unsuccessful attempt in 1980 to license CP/M for the IBM PC.

Gary Kildall was born and grew up in Seattle, Washington, where his family operated a seafaring school. His father, Joseph Kildall, was a captain of Norwegian heritage. His mother Emma was half-Swedish – Gary's grandmother was born in Långbäck in Skellefteå Municipality but emigrated to Canada at 23 years of age.

Gary attended the University of Washington (UW) hoping to become a mathematics teacher, but became increasingly interested in computer technology. After receiving his degree, he fulfilled a draft obligation to the United States Navy by teaching at the Naval Postgraduate School (NPS) in Monterey, California. Being within an hours' drive of Silicon Valley, Kildall heard about the first commercially available microprocessor, the Intel 4004. He bought one of the processors and began writing experimental programs for it. To learn more about the processors, he worked at Intel as a consultant on his days off.

Tim Paterson (born 1956) is an American computer programmer, best known as the original author of MS-DOS, the most widely used personal computer operating system in the 1980s.

Paterson was educated in the Seattle Public Schools, graduating from Ingraham High School in 1974. He attended the University of Washington, working as a repair technician for The Retail Computer Store in the Green Lake area of Seattle, Washington, and graduated magna cum laude with a degree in Computer Science in June 1978. He went to work for Seattle Computer Products as a designer and engineer. He designed a schematic of Microsoft's Z-80 SoftCard which had a Z80 CPU and ran the CP/M operating system on an Apple II.

A month later, Intel released the 8086 CPU, and Paterson went to work designing an S-100 8086 board, which went to market in November 1979. The only commercial software that existed for the board was a standalone version of Microsoft BASIC. The standard CP/M operating system at the time was not available for this CPU and without a true operating system, sales were slow. Paterson began work on QDOS (Quick and Dirty Operating System) in April 1980 to fill that void, copying the APIs of CP/M from sources including the published CP/M manual so that it would be highly compatible. QDOS was soon renamed as 86-DOS. Version 0.10 was complete by July 1980. By version 1.14 86-DOS had grown to 4,000 lines of assembly code. In December 1980 Microsoft secured the rights to market 86-DOS to other hardware manufacturers.