Butler W. Lampson

Developer of the Berkeley Timesharing System for Scientific Data Systems' SDS 940 computer, Lampson was part of Project GENIE at UC Berkeley during the 1960s, where he and Peter Deutsch created that system in 1965.

Lampson was one of the founding members of Xerox PARC in 1970, where he worked in the Computer Science Laboratory (CSL). His now-famous vision of a personal computer was captured in the 1972 memo entitled "Why Alto?". In 1973, the Xerox Alto, with its three-button mouse and full-page-sized monitor, was born, and is now considered to be the first actual personal computer (at least in terms of what has become the "canonical" GUI mode of operation).