For those interested in #emacs you might get a kick reading
https://www.multicians.org/mepap.html
It's an in-depth brain dump by Bernard S. Greenberg, author of #multics emacs c.a. 1979. His was the first Emacs to use lisp as it's extension language and probably the only one to have it's source code comments in a mixture of Yiddish and #Latin.
Gives background on #teco and the early creation of Emacs that was NOT done by #rms
I happened to use this as an programming intern around 1981
Sadly, the source which used to be available here http://web.mit.edu/afs/net/dev/reference/multics/ldd/unb/source/ seems to no longer be available (afs retired?)
If anyone can find the source, let me know.