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Ken Thompson

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Ken Thompson is a pioneering figure in the history of computer science. Born on February 4, 1943, in New Orleans, Louisiana, he showed an early interest in logic. As a child, he solved arithmetic problems using binary, which is a base-2 numbering system.

Pdp7-oslo-2005
Pdp7-oslo-2005

He later studied at the University of California, Berkeley. He earned a Bachelor of Science in 1965 and a master's degree in 1966. His studies focused on electrical engineering and computer sciences. Thompson is widely considered one of the greatest programmers of all time.

Much of Thompson's career was spent at Bell Labs. In the 1960s, he worked on the Multics operating system with Dennis Ritchie. After Bell Labs withdrew from the Multics project, Thompson found an old PDP-7 machine. He used it to rewrite his video game, Space Travel. This work eventually led to the creation of the Unix operating system.

Version 6 Unix SIMH PDP11 Emulation KEN
Version 6 Unix SIMH PDP11 Emulation KEN

Thompson and a team including Ritchie and Rudd Canaday developed several core features. These included a hierarchical file system and a command-line interpreter. They also created pipes, which allow for easy inter-process communication.

Thompson made several major contributions to programming languages and text processing. He created the B programming language to provide a system programming language for Unix. B served as a direct predecessor to the C language. He also performed foundational work on regular expressions. These are patterns used to search and manipulate text. Thompson developed the editor QED, which used these expressions. He also created Thompson's construction algorithm. This algorithm converts regular expressions into nondeterministic finite automata to speed up matching. Most modern programs still use a variant of his notation.

His work expanded into hardware and complex computing systems. In the 1970s, Thompson helped install Version 6 Unix at UC Berkeley. This helped lead to the Berkeley Software Distribution, or BSD. He also wrote the initial version of Berkeley Pascal in 1976. Later, Thompson focused on the design of Plan 9 from Bell Labs.

Plan 9 from Bell Labs (with acme)
Plan 9 from Bell Labs (with acme)

Plan 9 was intended to replace Unix by applying Unix principles more broadly. He also worked on the Inferno operating system, which used a portable virtual machine. In 2006, he joined Google, where he co-developed the Go programming language.

Thompson also had a deep interest in computer chess. In 1971, he wrote a chess program for the first version of Unix. He and Joseph Condon later created Belle, a world champion chess computer.

Pdp7-oslo-2005
Pdp7-oslo-2005

Thompson also developed endgame tablebases. These are databases that allow computers to make perfect moves in specific chess endings. He provided results for 4, 5, and 6-piece endings on CD-ROM. His work in this field was so significant that the ICGA Journal dedicated an issue to it in 2001. He even helped implement Turochamp, a program designed by Alan Turing in 1948.

In the field of digital communication, Thompson's work is nearly universal. In 1992, he and Rob Pike developed the UTF-8 encoding scheme. This is a method for representing text in a way that computers can process. UTF-8 has become the dominant form of Unicode encoding. In 2019, it accounted for more than 90% of all web pages. This makes his work essential to the modern World Wide Web. His contributions helped create the standards that allow different systems to share information.

Thompson's career has been marked by many prestigious honors. In 1983, he and Dennis Ritchie received the Turing Award. This award recognized their development of generic operating systems theory. During his speech, he described a security concept known as the Thompson hack. This involves a compiler backdoor, also called a trusting trust attack. He has also received the IEEE Richard W. Hamming Medal and the National Medal of Technology.

Plan 9 from Bell Labs (with acme)
Plan 9 from Bell Labs (with acme)

His work continues to guide the way engineers use computers today.

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