Who created UNIX?

I came across this email archived somewhere on the net. For those of you interested, the source is HERE.
For the rest you lazy bas*****, the text of the email is copied below:

From: dmr@alice.att.com (Dennis Ritchie)
Subject: re: UNIX
Message-ID: <11613@alice.att.com>
Date: 14 Nov 90 05:53:03 GMT
Organization: AT&T Bell Laboratories, Murray Hill NJ

I read,

> Looks like folks are now beginning to credit the
> development of UNIX to Kernighan and Ritchie, but
> I thought the principal investigators were
> *Thompson* and Ritchie.  Did something change?

The differences between Kernighan Ritchie Thompson
are real but very subtle. We all look alike (middle
aged with scruffy graying beards).  Note these
distinctions:

-- Kernighan is slimmest, Ritchie middlest, Thompson
  heaviest in body build
-- Ritchie got contacts a couple of years ago and so
  is the only current non-glasses wearer
-- Thompson wouldn't touch netnews with a pole,
  Kernighan secretly gets misc.invest and misc.taxes
  mailed to him, Ritchie reads it more than is good
  for him and occasionally contributes
-- Ritchie is the only one who has met five people
  who have appeared on David Letterman (Penn,
  Teller, Rob Pike, Mayor Koch, and the guy who
  raised the biggest hog in Ohio)
-- Kernighan has written ten times as much readable
  prose as has Ritchie, Ritchie ten times as much as
  Thompson.  It's tempting to say that the reverse
  proportions hold for code, but in fact Kernighan
  and Ritchie are more nearly tied and Thompson
  wipes us both out.

       Dennis