Who is Dennis Ritchie and Why should I care?

You can check Wikipedia for the fuller explanation, but here's the summary: He was a researcher at Bell Labs. While he was there, he worked on the Multics system, and as an offshoot, created the C language and the Unix operating system. The C language was not tightly tied to the specific system it came from, which meant that things written in it could reasonably be ported from one set of hardware to another.

He, Ken Thompson and Brian Kernighan are among the set of people whose creations made modern computation possible. I throw into that list Bob Metcalfe (ethernet) and Douglas Engelbart (windowing systems and the mouse). Others came along after and made things better, smaller, faster, more integrated and more beautiful, which is all very important, but Ritchie is among those who made things possible. He will be missed.

Dennis MacAlistair Ritchie 1941-2011