Ask HN: What software stack is most similar to the Lisp Machines?

GNU Emacs' software stack doesn't look similar to the Lisp Machine in any way. Similarity: Emacs Lisp is a small language based on Maclisp. The MIT Lisp Machine was developed in Zetalisp and later in Common Lisp. as such both are written in a dialect of Lisp (GNU Emacs has also some C code). But both dialects are very different.

As such basically ALL software of the MIT Lisp Machine is heavily object-oriented - unlike GNU Emacs. It uses an extensive graphical/textual GUI layer and abstractions like applications, command loops, servers, clients, ... On the Lisp Machine an editor is an application, but not the main abstraction (unlike GNU Emacs) - even the Listener on Lisp Machine is not in any way related to Emacs (minus some keyboard commands).

Thus the closest software stack to the Lisp Machine are by far Common Lisp + McCLIM + McCLIM-applications (like the McCLIM listener and others) and Common Lisp + CLIM + CLIM-environment.