Dennis M. Ritchie


DMR picture

In Memoriam

Dennis died in early October, 2011. This is a note from his sister and brothers:

As Dennis's siblings, Lynn, John, and Bill Ritchie--on behalf of the entire Ritchie family--we wanted to convey to all of you how deeply moved, astonished, and appreciative we are of the loving tributes to Dennis that we have been reading. We can confirm what we keep hearing again and again:

Dennis was an unfailingly kind, sweet, unassuming, and generous brother--and of course a complete geek. He had a hilariously dry sense of humor, and a keen appreciation for life's absurdities--though his world view was entirely devoid of cynicism or mean-spiritedness.

We are terribly sad to have lost him, but touched beyond words to realize what a mark he made on the world, and how well his gentle personality--beyond his accomplishments--seems to be understood.

Lynn, John, and Bill Ritchie


For many years, I worked in the Computing Sciences Research Center of Bell Labs. On October 2005, a reorganization redistributed this group, and I'm now with the center called by the slightly ungainly name of Convergence, Software and Computer Science Laboratory (but still in the same office). This experience has been more varied than it might seem; here's some of the history:

Old Bell System logo
When I joined in 1967, Bell Labs was a corporation jointly owned by American Telephone and Telegraph Company and its subsidiary Western Electric. Its official name was Bell Telephone Laboratories, Incorporated.

New Bell System logo
Soon after, Ken Thompson, together with me and others, first started work on Unix. Also soon after, AT&T, which still owned most of the Bell System, updated its logo (I doubt the events were related). The new logo just updated the image; corporate structure remained the same. The material published by us during the period up to 1984 used this Bell logo and the name "Bell Laboratories."

AT&T logo
In 1984, AT&T, under a negotiated consent decree, divested the local telephone companies it had owned and in the process gave up the Bell logo and the Bell name except in connection with Bell Laboratories. Bell Telephone Laboratories Inc. was dissolved as a corporation and became an integrated unit of AT&T. We lost the Wehrmacht helmet and gained the Deathstar, and now identified ourselves as working at "AT&T Bell Laboratories."

Lucent logo
In 1996, AT&T (this time voluntarily) spun off its systems and technology organizations into Lucent Technologies, while AT&T kept the services business. Bell Labs stayed mostly with Lucent, though some of our colleagues helped form a new AT&T labs, much as some of us went to Bellcore in 1984. The new corporate logo usually includes the line "Bell Labs Innovations."

Alcatel-Lucent logo
Lucent and Alcatel merged as of Dec 1, 2006. Another new name and logo! and still the same office.

Bell Labs has remained a remarkably good place to do work that has enduring impact over the long run, no matter what the company, the courts, the PR types or upper management decide should be our name and logo on a given day or year.

Some material

Various things I've been involved with are available in HTML, PostScript or PDF. Some are papers of mine or by others, some are just interesting incunabula. They're organized by category.

Unix papers and writings, approximately chronological

C and its immediate ancestors

Interesting other things: architecture, editors, adventures

Plan 9 and Inferno

Links I've gathered


A brief biography, in first person instead of obituary style.


bibtex format or html format .

Fiddled: May 2006 to add organization changes; March 2002, to add the HOPL talk link, July 2002 to add the C tutorial paper, October 2002 to add the ICGA paper, January 2003 to add the Portability paper, April 2003 to add the Kleine material, October 2003 for additional portability papers.
December 2006 to add new Alcatel-Lucent logo.