Montgomery Emacs was the first I knew of; it started on PDP-11 UNIX. According to: https://github.com/larsbrinkhoff/emacs-history/blob/sources/docs/Montgomery… Montgomery Emacs started in 1980 or so; here: http://ana-3.lcs.mit.edu/~jnc/tech/unix/emacs/emacs.doc is a manual from May, 1981. It had pretty full EMACS functionality, but the editor was not written in an implementation language of any kind (like the original, and like much later GNU Emacs); it was written in C. It did have macros for extensions, but they were written in Emacs commands, so, like the TECO that the original was written in, their source looks kind of like line noise. (Does anyone young even know what line noise looks like any more? I feel so old - and I'm a youngster compared to McIlroy!) I don't think it was widespread, but there was a TECO on the PDP-11 UNIXes at MIT; until Montgomery Emacs arrived, it was the primary editor used on those machines. Not that most people used TECO commands for editing; early on, they added '^R mode' to the UNIX TECO, similar to the one on ITS TECO, and a macro package was written for it (in TECO - so again, the source looks like line noise); the command set was like a stripped down EMACS - about a dozen command characters total; see the table about a page down here: http://ana-3.lcs.mit.edu/~jnc/tech/unix/teco/help All the source, and documentation, such as it is, it available, here: http://ana-3.lcs.mit.edu/~jnc/tech/unix/teco/ but don't even think about running it. It's written in MACRO-11, and it used a version of that hacked at MIT to run on UNIX. To build new versions of that, you need a special linker - written in BCPL. So you also need the UNIX BCPL compiler. Noel