@tomjennings

I'm not sure what part is surprising here. Definitely Emacs arose on top of TECO via Control-R mode as described. I guess people are surprised there was something before emacs-lisp?

There was one semester of Sussman's course in between the old 6.031 and the revised 6.001 where they had been on an 11/45 and wanted to move to the 10, and I packaged up a thing called MinEmacs (a mini-emacs) that was not extensible and just had a basic set of commands I thought would keep people from getting confused.

Stallman did NOT like my packaging. He said that Emacs was not about the command set and that it could have vi's command set for all he cared, but that it was about extensibility [edit: i should've said customizability here, though both, the ability of users to program it, in other words. Sorry I have no quote.], and that I should not use reference to Emacs for what I did. I had been worried that some region commands were a bit surprising because Emacs did not visibly display the region and it was often baffling what happened to the region. He wrote a library called Novice that he said was the right way to do this. With it loaded, when you did one of the worrisome commands (which were still disabled by default) it would ask you if you knew what you were doing and wanted to turn the command on. This behavior became a standard part of emacs when the port was done to emacs-lisp, so there is no novice library now. But at the time it was a separately loadable thing.

I tell the story mainly because it gives a sense of what the identifying characteristic was of Lisp as I understood it based on his strong reaction to what I'd done.