Dennis Ritchie: Computer software pioneer

He described his 'C' programming language as 'quirky, flawed and an enormous success'

Marcus Williamson
Saturday 22 October 2011 08:44

If you are reading today's Independent on a PC, Mac, smartphone or tablet computer, it is Dennis Ritchie whom you can thank for his role in bringing you much of the technology that made possible these devices and the software which runs on them.

His two greatest contributions to the world of computing have been the invention of the C programming language and his work in the development of the Unix operating system, both of which have provided the basis of the software running on the majority of recent computers.

Dennis Ritchie was born in Bronxville, New York in 1941. His father, Alistair Ritchie, was an electronics engineer and author of an important early text on data-switching systems. Ritchie read physics and applied mathematics at Harvard University, graduating in 1963 and obtaining his doctorate five years later. In 1967 he joined Bell Laboratories, a research facility owned at the time by AT&T and Western Electric, where his father already worked.

Here he collaborated on the Multiplexed Information and Computing Service ("MULTICS") project, intended to create a next-generation multi-user computer operating system. By 1970 the team had a version of the system working but it would only support one user, so they jokingly dubbed it "UNICS". This was soon truncated to just "Unix", a name which stuck and by which the operating system is still known today in a wide range of variants, including the now ubiquitous Linux, launched 21 years later by Linus Torvalds.

The project also saw the creation, by Ritchie's colleague Ken Thompson, of one of the earliest computer video games, named Space Travel, which involved piloting a spaceship through the solar system. The program was instrumental in motivating the development of Unix and could be considered as the first application on their newly-developed operating system.

It was around the same time that Ritchie and Thomson realised there was a need for a programming language which would allow writing software which could run on more than one kind of computer. With the new language, called simply "C" – as the logical successor to the previous language "B" – it was now possible to create programs that were "portable" between one machine and another.

The standard textbook, The C Programming Language, which Ritchie co-authored with Brian Kernighan, was first published in 1978 and has remained in print ever since. In a 1993 paper on the subject, Ritchie described his invention as "quirky, flawed, and an enormous success", adding that "While accidents of history surely helped, it evidently satisfied a need for a system implementation language efficient enough to displace assembly language, yet sufficiently abstract and fluent to describe algorithms and interactions in a wide variety of environments."

The Association for Computing Machinery presented Ritchie and Thompson with its Turing Award in 1983, in recognition of their contribution to the development of operating systems in general and Unix, in particular. In his acceptance lecture Ritchie explained modestly that "our intent was to create a pleasant computing environment for ourselves, and our hope was that others liked it." This was followed in 1990 with an award from the Institute of Electrical and Electronics Engineers. Then, in 1998, the pair received the National Medal of Technology and Innovation, presented by President Clinton for "enhancing American leadership in the Information Age".

Explaining his choice of career in a press interview, he said: "I started out interested in physics, and still maintain an amateur interest in keeping up with what's happening at its edges. Sometime in college and early grad school, I spent a lot of time in theoretical computer science (Turing machines, complexity theory). Meanwhile I also became more fascinated with real computers and, I suppose, the immediacy of the experience they provided: when you write a program, you can see what it does right away."

Ritchie retired as head of Lucent Technologies System Software Research Department in 2007 and had recently coped with treatment for prostatecancer and heart disease. Rob Pike, a former colleague at Bell Laboratories, paid tribute to him, saying, "He was a quiet and mostly private man, but he was also my friend, colleague, andcollaborator, and the world has lost a truly great mind."

Dennis Ritchie, computer software pioneer: born Bronxville, New York 9 September 1941; died Berkeley Heights, New Jersey 8 October 2011.

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