I had heard that Dennis Ritchie, co-creator of Unix/C/Plan9/Inferno,
had "retired."  While searching the Internet seeking confirmation, I
came across a couple of fun YouTube videos.

This first one features Thompson and Ritchie explaining what a
system is (i.e. kernel, shell, utilities).  Ritchie mentions how Unix
enables the formation of programming communities.  I think
Stallman makes a cameo appearance.
http://www.youtube.com/watch?v=7FjX7r5icV8

This second video is about Rob Pike's Blit.
http://www.youtube.com/watch?v=waTL1abCm9I