Dennis Ritchie

Dennis MacAlistair Ritchie
File:Dennis Ritchie 2011.jpg Dennis Ritchie, 2011
Born	(1941-09-09)September 9, 1941 Bronxville, New York, U.S.
Died	c. Berkeley Heights, New Jersey, U.S.
Nationality	American
Fields	Computer science
Institutions	Lucent Technologies Bell Labs
Alma mater	Harvard University (Ph.D., 1968)
Known for	ALTRAN B BCPL C Multics Unix
Notable awards	Turing Award (1983) National Medal of Technology (1998) IEEE Richard W. Hamming Medal (1990) Computer Pioneer Award (1994) Computer History Museum Fellow (1997) Harold Pender Award (2003) Japan Prize (2011)

Dennis MacAlistair Ritchie (September 9, 1941 – c. October 12, 2011) was an American computer scientist. He created the C programming language and, with long-time colleague Ken Thompson, the Unix operating system. 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.

Personal life

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. He graduated from Harvard University with degrees in physics and applied mathematics.

Career

Ken Thompson (left) and Dennis Ritchie (right)

Version 7 Unix for the PDP-11, including Dennis Ritchie's home directory: /usr/dmr

In 1967, Ritchie began working at the Bell Labs Computing Sciences Research Center, and in 1968, he defended his PhD thesis on "Program Structure and Computational Complexity" at Harvard under the supervision of Patrick C. Fischer. However, Ritchie never officially received his PhD degree.

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. They were so influential on Research Unix that Doug McIlroy later wrote, "The names of Ritchie and Thompson may safely be assumed to be attached to almost everything not otherwise attributed."

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.

Ritchie has described a 1970s collaboration with James Reeds and Robert Morris on a ciphertext-only attack on the M-209 US cipher machine that could solve messages of at least 2000–2500 letters. Ritchie relates that, after discussions with the NSA, the authors decided not to publish it, as they were told the principle was applicable to machines then still in use by foreign governments.

Views on computing

In an interview from 1999, Dennis Ritchie clarifies that he sees Linux and BSD operating systems as a continuation of the basis of the Unix operating system, and as derivatives of Unix:

I think the Linux phenomenon is quite delightful, because it draws so strongly on the basis that Unix provided. Linux seems to be among the healthiest of the direct Unix derivatives, though there are also the various BSD systems as well as the more official offerings from the workstation and mainframe manufacturers.

In the same interview, he states that he views both Unix and Linux as "the continuation of ideas that were started by Ken and me and many others, many years ago."

Awards

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". 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".

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."

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".

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.

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.

Death and legacy

File:Dennis Ritchie (right) Receiving Japan Prize.jpeg

Dennis Ritchie with Doug McIlroy (left) in May 2011

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. First news of his death came from his former colleague, Rob Pike. The cause and exact time of death have not been disclosed. He had been in frail health for several years following treatment for prostate cancer and heart disease. His death came a week after the death of Steve Jobs but did not receive as much media coverage. Following Ritchie's death, computer historian Paul E. Ceruzzi stated:

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.

In an interview shortly after Ritchie's death, long time colleague Brian Kernighan said Ritchie never expected C to be so significant. Kernighan reminded readers of how important a role C and UNIX had played in the development of later high-profile projects, such as the iPhone. Other testimonials to his influence followed.

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

• Usenix84 3 Small.jpg

  Ritchie engaged in conversation in a chalet in the mountains surrounding Salt Lake City at the 1984 Usenix conference.

• 

  At the same Usenix 1984 conference, Dennis Ritchie is visible in the middle, behind Steven Bellovin wearing a baseball hat.

Notable work

• C (programming language) on which many currently used languages and technologies are based.
• Unix a multiuser operating system. Several workalikes (commonly referred to as Unix-like systems) have been developed based on Unix's design. Some of these follow POSIX standards, again based on Unix.
• Unix Programmer's Manual (1971)
• The C Programming Language (book) (sometimes referred to as K&R; 1978 with Brian Kernighan)

External links

Listen to this article (info/dl)

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

More spoken articles

• 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 DMOZ