In some sense, you might consider it to be a crude one. If you configure your computer to boot directly into full screen emacs, never leave it, and do your damndest to interact only with in-process elisp, you might get some feel for what such a machine could be like.

It will also be a frustrating experience, since emacs was never really intended to be used in such a way. There’s going to be a lot of friction and limitations. Still, it’s a fun exercise for the right sort of person :)

You've just described the user interface to every cloud server I use.

0) ssh to server

1) run screen -RD

2) run user emacs in one screen, run user shells in emacs

3) run root emacs in another screen, run root shells in emacs

4) run top in another screen

5) run nvitop in another screen on gpu servers

6) try to remember not to leave tail -f foo.log running in any shells or server explodes after six months

Emacs predates Lisp machines, but a version of Emacs was written in Lisp and used there (EINE[1]). The point of a Lisp machine was that it ran Lisp natively or, at least, closer to native than, say, a 8086 DOS box.

1. https://en.wikipedia.org/wiki/EINE_and_ZWEI

EINE was the second Emacs (the first was TECO EMACS, an Emacs written in TECO macros) and EINE was the first one to be (completely) written in Lisp, on a GUI-based system.

It's a Lisp interpreter that happens to come with a text editor. I guess you can replace the text editing default skin, but I never tried it.