Brian Wilson Kernighan ( /ˈkɜrnɨhæn/; born 1942)^[1] is a Canadian computer scientist who worked at Bell Labs alongside Unix creators Ken Thompson and Dennis Ritchie and contributed to the development of Unix. He is also coauthor of the AWK and AMPL programming languages. The 'K' of K&R C and the 'K' in AWK both stand for 'Kernighan'. Brian Kernighan is currently a Professor at the Computer Science Department of Princeton University, where he is also the Undergraduate Department Representative.

Kernighan's name became widely known through co-authorship of the first book on the C programming language with Dennis Ritchie. Kernighan has said that he had no part in the design of the C language ("it's entirely Dennis Ritchie's work").^[2] He authored many Unix programs, including ditroff, and cron for Version 7 Unix.

In collaboration with Shen Lin he devised well-known heuristics for two NP-complete optimization problems: graph partitioning and the travelling salesman problem. (In a display of authorial equity, the former is usually called the Kernighan–Lin algorithm, while the latter is styled Lin–Kernighan.)

Kernighan was the software editor for Prentice Hall International. His "Software Tools" series spread the essence of 'C/Unix thinking' with makeovers for BASIC, FORTRAN, and Pascal - and most notably his 'Ratfor' (rational FORTRAN) was put in the public domain.

He has said that if stranded on an island with only one programming language it would have to be C.^[3]

Kernighan coined the term Unix in the 1970s. The original term he coined was Unics (for Uniplexed Information and Computing Service, a play on Multics), which was later changed to Unix.^{[citation needed]} Kernighan is also known as a coiner of the expression "What You See Is All You Get (WYSIAYG)", which is a sarcastic variant of the original "What You See Is What You Get" (WYSIWYG).^{[citation needed]} Kernighan's term is used to indicate that WYSIWYG systems might throw away information in a document that could be useful in other contexts.

Early life and education[link]

Born in Toronto, Kernighan attended the University of Toronto between 1960 and 1964, earning his Bachelor's degree in Engineering Physics.^[2] He received his PhD in electrical engineering from Princeton University, where he has held a professorship in the department of computer science since 2000. Each fall he teaches a course called "Computers in Our World", which introduces the fundamentals of computing to non-majors.

Summary of achievements[link]

• The first documented Hello, world program, in Kernighan's "A Tutorial Introduction to the Language B" (1972).
• The AWK programming language, along with Al Aho and Peter J. Weinberger, and its book The AWK Programming Language
• The AMPL programming language
• The Elements of Programming Style, with P. J. Plauger
• Ratfor
• Software Tools, a book and set of tools for Ratfor, cocreated in part with P. J. Plauger
• Software Tools in Pascal, a book and set of tools for Pascal, with P. J. Plauger
• The Unix Programming Environment, a tutorial book along with Rob Pike
• The C Programming Language along with C creator Dennis Ritchie, the first book on C
• The pic typesetting language for troff
• The eqn typesetting language for troff, along with Lorinda Cherry
• The Practice of Programming, with Rob Pike
• "Why Pascal is Not My Favorite Programming Language", a popular criticism of Niklaus Wirth's Pascal. Some parts of the criticism are obsolete due to ISO 7185 (Programming Languages - Pascal), the criticism was written before ISO 7185 was created. (AT&T Computing Science Technical Report #100)
• ditroff, or "device independent troff", which allowed troff to be used with any device
• The m4 macro processing language, with Dennis Ritchie

Writings[link]

• Software Tools (1976 with PJ Plauger)
• Software Tools in Pascal (1981 with PJ Plauger)
• The C Programming Language ('K&R') (1978, 1988 with Dennis M. Ritchie)
• The Elements of Programming Style (1974, 1978 with PJ Plauger)
• The Unix Programming Environment (1984 with Rob Pike)
• The AWK Programming Language (1988 with Al Aho and Peter J. Weinberger)
• The Practice of Programming (1999 with Rob Pike)
• AMPL: A Modeling Language for Mathematical Programming, 2nd Ed. (2003 with Robert Fourer and David Gay)
• D is for Digital: What a well-informed person should know about computers and communications (2011)

References[link]

1. ^ ^{a b} Lohr, Steve (31 October 2002). "To the Liberal Arts, He Adds Computer Science". The New York Times. http://www.nytimes.com/2002/10/31/technology/to-the-liberal-arts-he-adds-computer-science.html?pagewanted=all. "Mr. Kernighan, 60, is a renowned computer scientist" 
2. ^ ^{a b} Dolya, Aleksey (29 July 2003). "Interview with Brian Kernighan". Linux Journal. http://www.linuxjournal.com/article/7035. 
3. ^ Budiu, Mihai (July, 2000). "An Interview with Brian Kernighan". http://www-2.cs.cmu.edu/~mihaib/kernighan-interview/index.html. 

External links[link]

Wikiquote has a collection of quotations related to: Brian Kernighan

• Brian Kernighan's home page at Princeton U.
• Brian Kernighan's home page at Bell Labs
• "Why Pascal is Not My Favorite Programming Language" – By Brian Kernighan, AT&T Bell Labs, 2 April 1981
• "Leap In and Try Things" - Interview with Brian Kernighan – on "Harmony at Work Blog", October 2009.
• An Interview with Brian Kernighan – By Mihai Budiu, for PC Report Romania, August 2000
• Transcript of an interview with Brian Kernighan – Interview by Michael S. Mahoney
• Video - TechNetCast At Bell Labs: Dennis Ritchie and Brian Kernighan (1999-05-14)
• Video (Princeton University, September 7, 2003) - "Assembly for the Class of 2007: 'D is for Digital and Why It Matters'"
• A Descent into Limbo by Brian Kernighan
• Photos of Brian Kernighan
• Works by Brian Kernighan on Open Library at the Internet Archive
• Video interview with Brian Kernighan for Princeton Startup TV (03.20.2012)

Dennis MacAlistair Ritchie
Dennis Ritchie, 1999
Born	(1941-09-09)September 9, 1941 Bronxville, New York, U.S.
Died	found dead October 12, 2011(2011-10-12) (aged 70) Berkeley Heights, New Jersey, U.S.
Nationality	American
Fields	Computer science
Institutions	Lucent Technologies Bell Labs
Alma mater	Harvard University
Known for	ALTRAN B BCPL C Multics Unix
Notable awards	Turing Award National Medal of Technology

Dennis MacAlistair Ritchie (b. September 9, 1941; found dead October 12, 2011),^[1][2][3][4] was an American computer scientist who "helped shape the digital era."^[1] He created the C programming language and, with long-time colleague Ken Thompson, the Unix operating system.^[1] Ritchie and Thompson received the Turing Award from the ACM in 1983, the Hamming Medal from the IEEE in 1990 and the National Medal of Technology from President Clinton in 1999. Ritchie was the head of Lucent Technologies System Software Research Department when he retired in 2007. He was the 'R' in K&R C and commonly known by his username dmr.

Biography[link]

Ritchie was born in Bronxville, New York. His father was Alistair E. Ritchie, a longtime Bell Labs scientist and co-author of The Design of Switching Circuits on switching circuit theory. He moved with his family to Summit, New Jersey, as a child, where he graduated from Summit High School.^[5]

Ritchie graduated from Harvard University with degrees in physics and applied mathematics. In 1967, he began working at the Bell Labs Computing Sciences Research Center, and in 1968, he received a PhD from Harvard under the supervision of Patrick C. Fischer, his doctoral dissertation being "Program Structure and Computational Complexity".^[6]

Ritchie was best known as the creator of the C programming language, a key developer of the Unix operating system, and co-author of the book The C Programming Language, and was the 'R' in K&R (a common reference to the book's authors Kernighan and Ritchie). Ritchie worked together with Ken Thompson, the scientist credited with writing the original Unix; one of Ritchie's most important contributions to Unix was its porting to different machines and platforms.^[7]

The C language is widely used today in application, operating system, and embedded system development, and its influence is seen in most modern programming languages. Unix has also been influential, establishing concepts and principles that are now precepts of computing.

Awards[link]

Ken Thompson [L] and Dennis Ritchie [R]

In 1983, Ritchie and Thompson received the Turing Award for their development of generic operating systems theory and specifically for the implementation of the UNIX operating system. Ritchie's Turing Award lecture was titled "Reflections on Software Research".^[8] In 1990, both Ritchie and Thompson received the IEEE Richard W. Hamming Medal from the Institute of Electrical and Electronics Engineers (IEEE), "for the origination of the UNIX operating system and the C programming language".^[9]

In 1997, both Ritchie and Thompson were made Fellows of the Computer History Museum, "for co-creation of the UNIX operating system, and for development of the C programming language."

Thompson (left) and Ritchie (center) receiving the National Medal of Technology from President Clinton in 1999

On April 21, 1999, Thompson and Ritchie jointly received the National Medal of Technology of 1998 from President Bill Clinton for co-inventing the UNIX operating system and the C programming language which, according to the citation for the medal, "led to enormous advances in computer hardware, software, and networking systems and stimulated growth of an entire industry, thereby enhancing American leadership in the Information Age".^[10][11]

In 2005, the Industrial Research Institute awarded Ritchie with its Achievement Award in recognition of his contribution to science and technology, and to society generally, with his development of the Unix operating system.^[12]

In 2011, Ritchie, along with Thompson, was awarded the Japan Prize for Information and Communications for his work in the development of the Unix operating system.^[13]

Death and legacy[link]

Ritchie was found dead on October 12, 2011, at the age of 70 at his home in Berkeley Heights, New Jersey, where he lived alone.^[1] First news of his death came from his former colleague, Rob Pike.^[2][3] The cause and exact time of death have not been disclosed.^[14] He had been in frail health for several years following treatment for prostate cancer and heart disease.^{[1][2][15][16]} His death came a week after Steve Jobs', but did not receive as much media coverage.^[17][18] Computer historian Paul E. Ceruzzi said after his death: "Ritchie was under the radar. His name was not a household name at all, but... if you had a microscope and could look in a computer, you'd see his work everywhere inside."^[19]

In an interview shortly after Ritchie's death long time colleague Brian Kernighan said Ritchie never expected C to be so significant.^[20] Kernighan reminded readers of how important a role C and UNIX had played in the development of later high-profile projects, like the iPhone.^[21][22]

Other testimonials to his influence followed.^{[23][24][25][26]}

The Fedora 16 Linux distribution, which was released about a month after he died, was dedicated to his memory.^[27] FreeBSD 9.0, released January 12, 2012 was also dedicated in his memory.^[28]

Notable books[link]

• Unix Programmer's Manual (1971)
• The C Programming Language (1978 with Brian Kernighan; see K&R)

References[link]

External links[link]

Wikimedia Commons has media related to: Dennis Ritchie

Wikiquote has a collection of quotations related to: Dennis Ritchie

Listen to this article (info/dl)

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• Dennis Ritchie's home page at Bell Labs
• "The C Family of Languages: Interview with Dennis Ritchie, Bjarne Stroustrup, and James Gosling" – article in Java Report, 5(7), July 2000 and C++ Report, 12(7), July/August 2000
• "The Guru" – article in Linux Magazine, June 2001
• Dennis Ritchie's video interview June 2011
• Works by or about Dennis Ritchie in libraries (WorldCat catalog)
• Dennis Ritchie at Find a Grave
• Dennis Ritchie at the Open Directory Project

Kenneth Lane Thompson
Thompson (left) with Dennis Ritchie.
Born	(1943-02-04) February 4, 1943 (age 69) New Orleans, Louisiana, U.S.A.
Nationality	United States of America
Fields	Computer Science
Institutions	Bell Labs Entrisphere, Inc Google Inc.
Alma mater	University of California, Berkeley
Known for	Unix B (programming language) Belle (chess machine) UTF-8 Endgame tablebase
Notable awards	Turing Award National Medal of Technology Tsutomu Kanai Award

Kenneth Lane Thompson (born February 4, 1943), commonly referred to as ken in hacker circles,^[1] is an American pioneer of computer science. Having worked at Bell Labs for most of his career, Thompson is notable for his work with the B programming language (basing it mainly on the BCPL language he had used to write Unix while in the MULTICS project), the C programming language, and as one of the creators and early developers of the Unix and Plan 9 operating systems.

Other notable contributions included his work on regular expressions and early computer text editors QED and ed, his work on computer chess that included creation of endgame tablebases and the chess machine Belle, and most recently the co-creation of Google's programming language Go.

Biography[link]

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.^[2]

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.^[3]

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 default editor on Unix) contributed greatly to the eventual popularity of regular expressions, previously regarded mostly as a tool (or toy) for logicians.^{[citation needed]} 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.^[4]

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.^{[citation needed]}

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.

Thompson was elected to the National Academy of Engineering in 1980 for "designing UNIX, an operating systems whose efficiency, breadth, power, and style have guided a generation's exploitation of minicomputers."^[5]

Notes[link]

When Seibel (Coders at Work's interview) asked him: "How did you learn to program?" He said that: "I was always fascinated with logic and even in grade school I’d work on arithmetic problems in binary, stuff like that. Just because I was fascinated." ^[6]

Awards[link]

Thompson (left) and Ritchie (center) receiving the National Medal of Technology from President Clinton.

Turing Award[link]

In 1983, Thompson and Ritchie jointly received the Turing Award for their development of generic operating systems theory and specifically for the implementation of the UNIX operating system. His acceptance speech, "Reflections on Trusting Trust"^[7] presented the backdoor attack now known as the Thompson hack or trusting trust attack, and is widely considered a seminal computer security work in its own right.

IEEE Richard W. Hamming Medal[link]

In 1990, both Thompson and Dennis Ritchie received the IEEE Richard W. Hamming Medal from the Institute of Electrical and Electronics Engineers (IEEE), "for the origination of the UNIX operating system and the C programming language".^[8]

Fellow of the Computer History Museum[link]

In 1997, both Thompson and Ritchie were inducted as Fellows of the Computer History Museum for "the co-creation of the UNIX operating system, and for development of the C programming language."

National Medal of Technology[link]

On April 27, 1999, Thompson and Ritchie jointly received the 1998 National Medal of Technology from President Bill Clinton for co-inventing the UNIX operating system and the C programming language which together have led to enormous advances in computer hardware, software, and networking systems and stimulated growth of an entire industry, thereby enhancing American leadership in the Information Age.^[9][10]

Tsutomu Kanai Award[link]

In 1999, the Institute of Electrical and Electronics Engineers chose Thompson to receive the first Tsutomu Kanai Award for his role in creating the UNIX operating system, which for decades has been a key platform for distributed systems work.^[11]

Japan Prize[link]

In 2011 Ken Thompson, along with Dennis Ritchie, was awarded the Japan Prize for Information and Communications for the pioneering work in the development of Unix operating system.^[12]

References[link]

External links[link]

Wikiquote has a collection of quotations related to: Kenneth Thompson

Listen to this article (info/dl)

This audio file was created from a revision of the "Ken Thompson" article dated 2006-06-17, and does not reflect subsequent edits to the article. (Audio help)

More spoken articles

• Ken Thompson Bell Labs page
• Reflections on Trusting Trust 1983 Turing Award Lecture
• Unix and Beyond: An Interview with Ken Thompson IEEE Computer Society
• Ken Thompson: A Brief Introduction The Linux Information Project (LINFO)
• Computer Chess Comes of Age: Photos Computer History Museum
• Computer Chess Comes of Age: Video of Interview with Ken Thompson Computer History Museum
• Reading Chess paper by HS Baird and Ken Thompson on optical character recognition