[CalChris]

TECO was a character-oriented editor. Also, it was widely available on RSTS, RSX, RT-11, ... and other DEC systems in the mid-70s. There's a character cursor. So if you opened a file with:

  The quick brown fox jumped over the lazy.

The cursor would start before the T. 4C would position the cursor before the q. The 6D would delete quick . Then <esc><esc> would execute the command buffer.

These fingers of mine learned TECO before they learned vi and then found vi easier to learn as a result. Besides the basic editing syntax, it was a programmable editor, hence the TECO emacs macros.

Funny thing is that as fondly as I remember TECO, I've tried emacs a few times and have always worked my way back to vi/vim. I particularly like neovim now. I like using ex/command mode for doing bulk editing. Of course you can do the same thing in emacs but I've gotten used to it in vi. I remember programming TECO but I don't remember ever doing programmed editing.