> Provocative question: would a modern Lisp Machine necessarily use Lisp?

Seeing that not even "Original Gangster" Lisp Machine used Lisp ...

Both the Lambda and CADR are RISCy machines with very little specific to Lisp (the CADR was designed specifically to just run generic VM instructions, one cool hack on the CADR was to run PDP-10 instructions).

By Emacs you definitely mean GNU Emacs -- there are other implementations of Emacs. To most people, what the Lisp Machine was (is?), was a full operating system with editor, compiler, debugger and very easy access to all levels of the system. Lisp .. wasn't the really interesting thing, Smalltalk, Oberon .. share the same idea.

> Dedicated hardware? I doubt that we’ll ever see that again, although of course I could be wrong.

Since we're now building specialized hardware for AI, emergence of languages like Mojo that take advantage of hardware architecture and what I interpret as a renewed interest in FPGAs perhaps specialized hardware is making a comeback.

If I understand computing history correctly, chip manufacturers like Intel optimized their chips for C language compilers to take advantage of economies of scale created by C/Unix popularity. This came with the cost of killing off lisp/smalltalk specialized hardware that gave these high level languages decent performance.

Alan Kay famously said that people who are serious about their software should make their own hardware.