It is likely that most readers have never heard of Gary Kildall. Since I am older than dirt, I can remember watching Gary on the early computer television show called Computer Chronicles. I also used an early desktop know as the Kaypro II, which used the CP/M operating system. CP/M, developed by Gary, was the first operating system for personal computers. That introduction to computing began a 32 year fascination with computers.
Gary Kildal died in 1992. Recently he was recognized posthumously, by IEEE, for development of CP/M and invention of the computer BIOS. I have provided links below to introduce you to this giant in early personal computer development.