Dennis Ritchie

Dennis Ritchie Photo

Dennis Ritchie invented “C Programming Language” and “UNIX Operating System”

Dennis MacAlistair Ritchie was a renowned American computer scientist, best remembered for creating the “C” computer programming language and his contributions to the development of UNIX Operating System. He was born in Bronxville, New York in 1941. His father, Alistair Ritchie, was a scientist at Bell Labs and wrote a book on circuit theory. Ritchie’s family moved to New Jersey when he was a child. There he studied at Summit High School and later obtained a BS degree in Physics in 1963 and a Ph.D. in Applied Mathematics in 1967, both from Harvard University.

Ritchie and his associate Ken Thompson worked together at AT&T Bell Labs to create the Unix Computer Operating System. This is one of the two most significant achievements of Ritchie’s career, the other being the development of the C Programming Language. C was the descendant of the B programming language developed by Bell Labs. It was meant to be a “higher level” computer language and was the basis on which the UNIX Operating System was run. Thompson and Ritchie gained tremendous success with UNIX and the C Language. Before C, there was hardly any standardization in the computer industry. Computer programs were very specific to a particular type of hardware and could not be run on just any computer. UNIX and C served to combine and standardize the scattered bits and piece of software in the industry.

C was a powerful, multi-purpose language and combined with UNIX, their widespread impact and influence is evident in almost every aspect of the computing industry today. For instance, languages which came later (such as Java and C++) were derived from the C language, browser codes are all written in C, and the UNIX kernel (an important basis on which is the internet works) is also written in C. Even Microsoft Windows was initially written in C. Both of Apple Inc’s Operating Systems (called iOS and MAC OS X) are based on the UNIX system. There is no doubt about the impact of Ritchie’s contributions on the computing industry and the world. It would be fair to say that he has significantly altered the course of the computing industry’s history.

As the popularity of the C language rose, the use of C and UNIX spread throughout the industry and it began to be taught to computer engineers in universities. This was in large part due to the success of Kerninghan and Ritchie’s book titled “The C Programming Language“. This book was published in 1978, and served as a comprehensive manual for learning how to use C. The book’s authors are often collectively referred to as “K & R”. This book was so successful that it’s been translated into 20 different languages. It’s popularity is due to the fact that it’s easy to use and understand.

When AT&T was restructured, Ritchie was transferred to a newly created division called Lucent Technologies, where he worked until his retirement in 2007 as Head of System Software Research Department. Ritchie’s list of awards and accolades is extensive. He is a Fellow of the Computer History Museum, and recipient of the National Medal of Technology from President Bill Clinton, Achievement Award by the Industrial Research Institute and the Japan Prize for Information and Communications.

By nature, Dennis Ritchie was a humble, polite and well liked person. He looked like a typical IT guru with long hair and a beard. He preferred to start working around noon and went home and worked into the late hours of the night. Ritchie suffered from poor health for the last few years of his life and died in October 2011 at the age of 70. His legacy lives on in the form of the prevalent application of his contributions to modern computing.


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