Gary Kildall

In 1973, while working for Intel Corp., Kildall created the first computer operating system (OS) to see popular use. Seeking a way to control the storage and retrieval of data on floppy disks, Kildall realized the need for a basic OS that could accept and interpret operator commands using less than 4k of memory. Originally named Control Program/Monitor, the initials later came to stand for Control Program/Microprocessor or Microcomputer. But it was best known as CP/M, and the programming language he developed for it was called PL/M. Intel saw no use for CP/M and gave the rights to Kildall, who sold it himself, eventually through his own company, Intergalactic Digital Research (later Digital Research Inc.). CP/M proved to be the OS that fueled the birth of the PC. For the first few years, it was used on virtually every PC manufactured.