Greg 'groggy' Lehey wroteÖ
>> I think just about every DEC computer had a version of TECO, right?
> I don't recall seeing it on our PDP-8 and -12.  Does anybody else?

I found this:

  "TECO, the text editor, was included in the standard OS/8
  distributions and is a general purpose language (the Emacs editor
  began as a set of TECO macros!).  The story of TECO on the PDP-8 is
  convoluted.  Russ Hamm implemented TECO under his OS8 (without a
  slash) system, and then gave a listing to Don Baccus at the Oregon
  Museum of Science and Industry (OMSI) who, along with Barry Smith
  ported it to PS/8.  This was the beginning of what became Oregon
  Software, later famous for OMSI Pascal.

  Richard F. Lary and Stan Rabinowitz made OS/8 TECO more compatible
  with other versions of TECO, and the result of this work is the
  version distributed by DECUS (catalog number 110450 is the
  manual). RT-11 TECO for the PDP-11 is a port of this code."

http://homepage.cs.uiowa.edu/~jones/pdp8/faqs/