His two passions in life were flying and computers. He was a bit of a cult figure in his day, as the author of CP/M (his most noted accomplishment), but the scene was comparatively tiny back then.

See Eulogy for Gary Kildall (describing him as running at 100 megahertz back when most people thought a megahertz had something to do with radios and a clock speed that fast was almost unimaginable).

Born in Seattle, Gary was from childhood onward always a tinkerer. Following his graduation from the University of Washington in 1972, he joined the Navy, who promptly appointed him to be a Computer Science instructor in Monterey. Whilst there, he and his students began to experiment with Intel's 4004 microprocessor chip.

He created PL/M for the IBM 360 and later developed a version for the 8008 chip. IBM continued to ask him to develop software, and gave him an Intellec-80 for use at the school, which he used not only as part of his teaching, but also for continued experimentation.

In 1973 Intel were given a Shugart 8" floppy disk. Gary and his friend, John Torode, built an interface to an Intellec-80 computer. Subsequently, he and his students wrote a control program, which he called CP/M (Control Program/Microcomputer), to enable him to read and write files to and from the disk.

Birth of an OS

In 1976 he founded Intergalactic Digital Research, and designed floppy disk systems for several manufacturers. He rewrote CP/M and made it hardware-independent by creating a BIOS. With the addition of compilers and debuggers, CP/M became a full-blown computer development system. He and his wife then started a company called Galactic Digital Research Inc. (later Digital Research) to market his products. By 1977, several manufacturers were including CP/M with their systems.

He was approached by IBM in 1980 to complete the production of CP/M-86, a version for the new 8086 chip, but various delays meant that he could not meet their requirements.

When IBM later asked him to port CP/M to their 8008 for the development of a PC, Gary was out, (allegedly) flying. His wife famously declined to sign a non-disclosure agreement, and demanded more money, at which point the IBM suits left. The delays involved enabled Bill Gates to obtain QDOS and use it to develop MS-DOS to win the contract. This was one of the pivotal points in Microsoft's success, and many have wondered what the world of personal computing would have looked like had Gary won the day.

Gary also developed GEM (the "Graphical Environment Manager") in 1983, which was a GUI similar in appearance to the Macintosh operating system. GEM was used in many hardware platforms, both the Intel PC and the Atari ST systems. In addition, he carried out a great deal of work in the software required for driving CD-ROM interfaces.

In 1991 he retired to Austin, Texas and became known as a philanthropist, although he became increasingly depressed and reclusive. He died on July 11, 1994, following a fall. His place in history is assured, however, as one who has helped make the computing environment what it is today.

Thanks to xunker for a correction.