Interlisp logo – A semi-circle of screens with the words Interlisp-D in the lower righthand corner

Please join the Medley Interlisp Users Group to ask questions and discuss Interlisp.

What is Medley Interlisp?

Medley Interlisp is the environment originally developed for the Xerox Lisp machines (called D-machines, names Dorado, Dolphin, Dandelion, Daybreak). The project was spun out to a company called Envos, which then turned into Venue.

It was the first IDE with a window/mouse/menu GUI, launched as a product from Xerox in 1980. It was a base from which AI applications were built, as well as a research project in its own right.

For example, Interlisp SEDIT is the canonical ancestral structure editor. Masterscope and the “file package” included system-management tools that combined features of version control and build systems, with comprehensive cross referencing support.

Medley was the last release of the Xerox Lisp environment, before the whole environment was renamed Medley. It was originally written in Interlisp (a dialect separate from the MACLISP/Common Lisp tradition, with its own ancestry), but later, Common Lisp also became part of the environment. Medley includes a WYSIWYG text editor (TEdit), email organizer (Lafite), performance tools (Spy) and many other libraries and user contributed code (from the 1980s).

What have we lost? A presentation from the 2020 Remote Chaos Experience conference highlights some of the interesting aspects of Interlisp. The presentation synopsis states it this way:

We have ended up in a world where UNIX and Windows have taken over, and most people have never experienced anything else. Over the years, though, many other system designs have come and gone, and some of those systems have had neat ideas that were nevertheless not enough to achieve commercial success. We will take you on a tour of a variety of those systems, talking about what makes them special.


Medley Interlisp documentation for is available in from here: Documentation.
Documentation on building and running the restored version of Medley Interlisp can be found here: ??


You can post questions and comments to the Medley Interlisp Users Group.

Bug And Issue Tracking

You can report or view bugs and issues by visiting the Medley Interlisp Issues page.