Ken Thompson

Ken Thompson

Dennis Ritchie

Dennis_MacAlistair_Ritchie_.jpg

He created the C programming language and, with long-time colleague Ken Thompson, the Unix operating system

Kenneth Lane Thompson (born February 4, 1943), commonly referred to as ken in hacker circles, is an American pioneer of computer science. Having worked at Bell Labs for most of his career, Thompson designed and implemented the original Unix operating system. He also invented the B programming language, the direct predecessor to the C programming language, and was one of the creators and early developers of the Plan 9 operating systems. Since 2006, Thompson works at Google, where he co-invented the Go programming language. Other notable contributions included his work on regular expressions and early computer text editors QED and ed, the definition of the UTF-8 encoding, his work on computer chess that included creation of endgame tablebases and the chess machine Belle.

Thompson was born in New Orleans. He received a Bachelor of Science in 1965 and a master's degree in 1966, both in Electrical Engineering and Computer Science, from the University of California, Berkeley, where his master's thesis advisor was Elwyn Berlekamp.In the 1960s, Thompson and Dennis Ritchie worked on the Multics operating system. While writing Multics, Thompson created the Bon programming language. The two left the Multics project when Bell Labs withdrew from it, but they used the experience from the project, and in 1969, Thompson and Ritchie became the principal creators of the Unix operating system. At this time, Thompson decided that Unix needed a system programming language and created B, a precursor to Ritchie's C.

Thompson had developed the CTSS version of the editor QED, which included regular expressions for searching text. QED and Thompson's later editor ed (the standard text editor on Unix) contributed greatly to the eventual popularity of regular expressions, previously regarded mostly as a tool (or toy) for logicians. Regular expressions became pervasive in Unix text processing programs (such as grep) and in modern programming languages such as Perl; they are also a central concept in Rob Pike's sam text editor. Almost all programs that work with regular expressions today use some variant of Thompson's notation for them.

Thompson also developed UTF-8 (a widely used character encoding scheme) together with Rob Pike in 1992. Along with Joseph Condon, he created the hardware and software for Belle, a world champion chess computer. He also wrote programs for generating the complete enumeration of chess endings, known as endgame tablebases, for all 4, 5, and 6-piece endings, allowing chess-playing computer programs to make "perfect" moves once a position stored in them is reached. Later, with the help of chess endgame expert John Roycroft, Thompson distributed his first results on CD-ROM. Thompson's style of programming has influenced others, notably in the terseness of his expressions and a preference for clear statements. In late 2000, Thompson retired from Bell Labs. He worked at Entrisphere, Inc as a fellow until 2006 and now works at Google as a Distinguished Engineer. Recent work has included the co-design of the Go programming language. Thompson was elected to the National Academy of Engineering in 1980 for "designing UNIX, an operating system whose efficiency, breadth, power, and style have guided a generation's exploitation of minicomputers."