My company bought me a Xerox 1108 Lisp Machine running Interlisp D in 1982. I write a commercial product for that environment that we sold for $5K, and it was a lot of fun. I run the latest Medley releases occasionally just for nostalgia. For present day hacking enjoyment I go with SBCL Common Lisp+Emacs, or Racket, or Python when I need the ecosystem.
Xerox really did a great job creating their Lisp Machines, a joy to develop on.
Xerox really did a great job creating their Lisp Machines, a joy to develop on.