Dennis M. Ritchie

Updated at: Feb. 13, 2011, 3:08 a.m.

Dennis M. Ritchie is head of the System Software Research department in the Computing Sciences Research Center of Bell Labs / Lucent Technologies in Murray Hill, NJ.

He was born Sept. 9, 1941 in Bronxville, N.Y., and received Bachelor's and advanced degrees from Harvard University, where as an undergraduate he concentrated in Physics and as a graduate student in Applied Mathematics. The subject of his 1968 doctoral thesis was subrecursive hierarchies of functions.

His undergraduate experience convinced him that he was not smart enough to be a physicist, and that computers were quite neat. His graduate school experience convinced him that he was not smart enough to be an expert in the theory of algorithms and also that he liked procedural languages better than functional ones.

He joined Bell Labs in 1967, following his father, Alistair E. Ritchie, who had a long career there. His most visible public accomplishment was as co-author of The Design of Switching Circuits, with W. Keister and S. Washburn; it was an influential book on switching theory and logic design just before the transistor era.

Soon after, he contributed to the Multics project, then a joint effort of Bell Labs, MIT, and General Electric. he helped with a compiler for the BCPL language on the Multics machine (GE 645) and on the GE 635 under the GECOS system. Also, he wrote the compiler for ALTRAN, a language and system for symbolic calculation.

Subsequently, he aided Ken Thompson in creating the Unix operating system. After Unix had become well established in the Bell System and in a number of educational, government and commercial installations, Steve Johnson and himself (helped by Ken) transported the operating system to the Interdata 8/32, thus demonstrating its portability, and laying the groundwork for the widespread growth of Unix: the Seventh Edition version from the Bell Labs research group was the basis for commercial Unix System V and also for the Unix BSD distributions from the University of California at Berkeley. The last important technical contribution he made to Unix was the Streams mechanism for interconnecting devices, protocols, and applications.

Early in the development of Unix, he added data types and new syntax to Thompson's B language, thus producing the new language C. C was the foundation for the portability of Unix, but it has become widely used in other contexts as well; much application and system development for computers of all sizes, from hand-held to supercomputer, uses it. There are unified U.S. and international standards for the language, and it is the basis for Stroustrup's work on its descendant C++.

Today, as a manager of a small group of researchers, he promote exploration of distributed operating systems, languages, and routing/switching hardware. The recent accomplishments of this group include the Plan 9 operating system, which was released in 1995, and the Inferno operating system, announced April 1996.

Awards include: ACM award for the outstanding paper of 1974 in systems and languages; IEEE Emmanuel Piore Award (1982), Bell Laboratories Fellow (1983); Association for Computing Machinery Turing Award (1983); ACM Software Systems Award (1983); C&C Foundation award of NEC (1989); IEEE Hamming Medal (1990). he was elected to the U. S. National Academy of Engineering in 1988. In April 1999 he received the U. S. National Medal of Technology. These were all awarded in conjunction with Ken Thompson.

Related Books

The C Programming Language

The C Programming Language: Based on Draft-Proposed ANSI C 2nd Ed.