From the code in your microwave to massive computing clusters, virtually all of our software can trace its ancestry back to this man's intellectual output.
I'm eternally grateful for his life and contributions to humanity.
Consider that every single person reading these words are doing so using technology he created -- after all, even if you're not on a UNIX derivative you're probably on an OS and web browser written in C.
How much code is written every day in C and its descendants? How much more in languages that themselves are written in C?
dmr is part of an very small group of computer scientists that truly changed the paradigm of computing for everyone everywhere (Turing, von Neumann, Engelbart, ...) As long as there are ones and zeros his name will be remembered.
The original Macintosh was programmed in assembler. As was MS-DOS and Windows up to version 3.1 (perhaps even in important parts in Win95?). The big boom of computing and the GUI had already happened. In the late 80s Turbo Pascal was really popular: http://en.wikipedia.org/wiki/Pascal_(programming_language) http://en.wikipedia.org/wiki/Turbo_Pascal
For GUI programming there was (and is) the Pascal dialect Delphi: http://en.wikipedia.org/wiki/Embarcadero_Delphi
What would the world look like if C would have been never invented? I guess our browsers would simply be coded in Turbo Pascal dialect.
And Visual Basic is still huge (#12 on langpop.com). Also someone could reasonably argue that from the concept and ideas SmallTalk and Lisp were way more influential than C.
That said, I feel a bit dirty to make this argument. Dennis Ritchie should be praised for his accomplishments.
I wonder what the Turbo Pascal compilers were written in...
With Unix and C , he has changed the way people think of computers and the way of talking to them.