When the world is mourning with the death of Steve Jobs, the world lost another tech pioneer Dennis Ritchie, the inventor of C and UNIX. To many geeks, Dennis’ role in the computer revolution is way more important than Steve.

Dennis Ritchie, the Bell Labs computer scientist who created the immensely popular C programming language and who was instrumental in the construction the well-known Unix operating system, died last weekend after a protracted illness. Ritchie was 70 years old.

Ritchie, who was born in a suburb of New York City, graduated from Harvard and later went on to earn a doctorate from the same institution while working at Bell Labs, which then belonged to AT&T (and is now part of the Alcatel-Lucent). There he joined forces with Ken Thompson and other Bell Labs colleagues to create the Unix operating system. Although early Unix evolved without the naming of progressively advanced versions, the birth of this operating system can be marked by the first edition of the Unix programmers’ manual, which was issued in November of 1971, almost 40 years ago.

Although AT&T had been engaged in the development of an advanced computer operating system called Multics in the late 1960s, corporate managers abandoned those efforts, making Thomson and Ritchie’s work on Unix that much more impressive. These researchers threw themselves into the development of Unix despite, rather than in response to, their employer’s leanings at the time. We should be thankful that Ritchie and his colleagues took such initiative and that they had the foresight and talent to build a system that was so simple, elegant, and portable that is survives today. Indeed, Unix has spawned dozens if not hundreds of direct derivatives and Unix-like operating systems, including Linux, which can now be found running everything from smartphones to supercomputers. Unix also underlies the current Macintosh operating system, OS X.

Ritchie’s work creating the C programming language took place at the same time and is closely tied to the early development of Unix. By 1973, Ritchie was able to rewrite the core of Unix, which had been programmed in assembly language, using C. In 1978, Brian Kernighan (another Bell Labs colleague) and Ritchie published The C Programming Language, which essentially defined the language (“K&R C”) and remains a classic on the C language and on good programming practice in general. For example, The C Programming Language established the widespread tradition of beginning instruction with an illustrative program that displays the words, “Hello, world.”

For their seminal work on Unix, Ritchie and Thompson received in 1983 the Association of Computing Machinery’s Turing Award. In 1990, the IEEE awarded Ritchie and Thompson the Richard W. Hamming Medal. Ritchie and Thompson’s work on Unix and C was also recognized at the highest level when President Bill Clinton awarded them the 1998 National Medal of Technology. And in May of this year, Ritchie and Thompson received the 2011 Japan Prize (which was also awarded to Tadamitsu Kishimoto and Toshio Hirano, who were honored for the discovery of interleukin-6).

Spectrum attended the Japan Prize awards ceremony and had an opportunity to ask Ritchie to reflect on some of the high points of his impressive career. During that interview, Ritchie admitted that Unix is far from being without flaws, although he didn’t attempt to enumerate them. “There are lots of little things—I don’t even want to think about going down the list,” he quipped. In December, Spectrum will be publishing a feature-length history of the development of the Unix operating system.

Rob Pike, a former member of the Unix team at Bell labs, informed the world of Ritchie’s death last night on Google+. There he wrote, “He was a quiet and mostly private man, but he was also my friend, colleague, and collaborator, and the world has lost a truly great mind.” A charming illustration of some of those qualities comes from David Madeo, who responded to Pike’s message by sharing this story:

I met Dennis Ritchie at a Usenix without knowing it. He had traded nametags with someone so I spent 30 minutes thinking “this guy really knows what he’s talking about.” Eventually, the other guy walked up and said, “I’m tired of dealing with your groupies” and switched the nametags back. I looked back down to realize who he was, the guy who not only wrote the book I used to learn C in freshman year, but invented the language in the first place. He apologized and said something along the lines that it was easier for him to have good conversations that way.