Arguably, the third most famous member of the Unix pantheon is Brian Kernighan. Although he did not, in fact, work on the development of the C language (he was the co-author along with Ritchie of the definitive book on C) his contributions were significant and seminal. I think of him as the ultimate tool builder—I have no idea if he would embrace that description—and master of the Unix Way™. After K&R, he's probably best known for
awk, a little language that is still in use today and has devoted adherents.
In a recent Computerphile video, Kernighan and Professor David Brailsford sit down to talk about Kernighan's career and what it was like to work at Bell Labs in the glory days.
Kernighan talks about the introduction of pipes into Unix and the dramatic difference it made in the way people thought of and performed computations. In some sense, pipes were a necessity. Memory was in such short supply in those days that you pretty much had to stitch together a bunch of small programs to get things done.
If you're at all interested in our shared history—and you should be—you will want to watch this video. It's a bit over 28 minutes so you'll have to schedule some time but it's well worth it.
UPDATE: Added link to video.