The Interlisp Programming Environment (1981) [pdf] | Hacker News Reader

The Interlisp Programming Environment (1981) [pdf]

ics.uci.edu

58 pointsgruseom10 comments

Interlisp was the so-called "west coast" Lisp that emphasized an interactive programming environment and in retrospect looks more like a hybrid between Smalltalk and Lisp than modern Lisp implementations. It was developed at PARC for a while. I don't know if there was cross-pollination between Interlisp and Smalltalk or if the similarity was a zeitgeist thing.

This article talks about the design values of the system and communicates the flavour of what a Smalltalkish Lisp would have been like.

As someone who's only read about this, I'd be interested in hearing from people who actually used it.

From 1986-88, I worked for Xerox AI Systems, the group that commercialized Interlisp-D. We (my personal contribution was relatively small) added Common Lisp to the system, along with SEdit, a friendlier-than-DEdit structure editor.

Interlisp-D went against the grain of most other Lisp implementations at the time:

* Byte-coded implementation interpreted in micro-code, for very compact compiled code (vs. RISC machines' larger, faster code)

* Tuned for interactive performance (vs. tuned for Gabriel benchmark performance)

* Managed code and structure editing (vs. text files and emacs)

In late 1988, Xerox tried to spin the Lisp/AI business out into a separate company named enVos. Envos crashed almost immediately:

http://www.the-scientist.com/?articles.view/articleNo/10590/...

Medley, the last release from enVos, hung on as a commercial product from Venue:

http://top2bottom.net/medley.html

It's very much like an early version of Smalltalk: monochrome, with an early-80s style GUI. There's a popup main menu with a surprising number of options, plus several editors, debugging tools, and a Smalltalk-like 'Transcript' window (for output). The system is image-based, so the running image could be stopped and restarted, even from a different machine.

More intriguingly - and again, analogous to Smalltalk - Interlisp is more than just another Lisp dialect: it's a complete operating system running atop a Lisp VM, with Lisp as the system language, from top to bottom. Awesome!

By today's standards, it's clunky (as one would expect), but if development had continued, I suspect the comparison to Symbolics Genera would be the analog of comparing a GUI desktop environment to a console-based one. Considering the richness of modern environments (have you seen Pharo or Squeak?), that could've been a seriously cool Lisp development platform...

Incidentally, ParEdit is based on Interlisp's SEdit (in Taylor Campbell's words, 'a real structure editor, not a cheesy imitation like paredit').

> I suspect the comparison to Symbolics Genera would be the analog of comparing a GUI desktop environment to a console-based one

Huh? The MIT-class Lisp Machines also had GUIs from the beginning. Clunky by modern standards, as you say, but definitely graphical.

Maybe I just don't get what analogy you're trying to draw.

Yes, you're right - I was mistaken (I was thinking of Slime/Emacs). Genera had a proper hierarchical window system - screenshots just don't do it justice!

Much of that is actually a decade or more older. It was then called BBN Lisp. The BBN team then went to Xerox PARC. There they also moved this Lisp onto the new personal workstations.

http://www.softwarepreservation.org/projects/LISP/bbnlisp

This gives the impression what they had in 1971:

http://www.softwarepreservation.org/projects/LISP/bbnlisp/Te...

I got a Xerox 1108 Lisp Machine running Interlisp-D in 1982 and enjoyed it greatly. It had knowledge of code like modern IDEs making code inspection and refactoring easier. Back then, it was like magic.

Now however, I prefer IntelliJ for Clojure and Java, and the similar IDE RubyMine for Ruby development. I think very good IDEs are a spiritual successor to the wonderful programming environment if my 1108.

Nice article. I have a Xerox 6085 "Daybreak" workstation that runs Interlisp.

An emulator exists, that runs on various *nix systems. It used to be available for noncommercial use under here http://www2.parc.com/isl/groups/nltt/medley/ but the links seem dead.

Email me if you want a copy... I also have it set up in a Debian image, ready-to-run.

Is it abandonware or is there still commercial interest in it?

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