Someone posted a chapter from Sam Williams’ book Free as in Freedom (online here), that discusses the early history of Emacs. The chapter, The Emacs Commune, is full of things I didn’t know about how Emacs evolved from the TECO editor.
We all know that Emacs started as a set of macros to the TECO editor (hence Editing MACroS) but there’s a lot more to the story. In the first place, the choice of the name Emacs involved more than just the obvious mnemonic. The choice was, in fact, chosen for efficiency reasons. You can read the chapter to see what that was.
You may also have heard that Guy Steele played an important role in the development of Emacs. That’s true, and, in a way, he started the whole thing, but the driving force was always Richard Stallman.
If you’re an Emacser, you owe it to yourself to take a look at this chapter if only so you’ll know where the editor that we love and depend on came from. Even early on, lots of people contributed, if only in the form of their own TECO macros. It turns out that the early standardization of those macros—in what was later to become Emacs—presented a political problem for Stallman. Read it and become enlightened.