2022 Medley Interlisp Annual Report


We have made considerable progress on the Interlisp software preservation project, and we want to offer tours and collaboration for those engaged in similar or related software preservation efforts.

Interlisp was an early and unique software development environment (IDE) developed in the 1970’s and 1980’s at Xerox PARC, and a testbed for novel software development tools. The Medley version of Interlisp-D was built as a portable Virtual Machine, which has allowed us to bring the system forward to run on a wide variety of modern hardware and operating systems.

Interlisp was also an environment that supported many novel applications, especially in Artificial Intelligence of the 1980s.

We are approaching the project as a general software-preservation-through-emulation project, starting with source code. While a “strict emulation” mode is possible, we’ve been focusing on an updated version that fixes some of the compatibility problems with modern hardware (keyboards, mice, etc.) and implements more modern modes of user interaction.


Advances over the last year include:

  • New versions of online.interlisp.org give users a virtual “Lisp machine” accessed through the browser without any software to install.
  • New versions of (open source, in GitHub) emulator and VM images with numerous improvements.
  • Support for virtual networking of the Xerox Network Systems (XNS) protocol stack (pre-dating TCP/IP, as well as the “PUP” (PARC Universal Packets).
  • Further work reviving classic Interlisp applications, including Rooms (desktop management), Notecards (Hypertext from the 80s, well before the Web), LOOPS (Lisp Object Oriented Programming System), melding Smalltalk style object inheritance with class-based knowledge engineering tools.
  • Continued integration of Common Lisp standard features with Interlisp development tools.
  • A large (but still unsorted) Zotero library of referenced texts, papers, documents, and presentations.
  • A new expanded Interlisp.Org website that documents the project, software history, goals, contributors, and other components.
  • Additional development of GitHub Interlisp organization and repositories that provide a record of issues, changes, bugs, and fixes.

Getting Involved

We meet weekly to discuss open issues and other agenda items. Meetings are recorded. We’d like to talk to others who might be interested in collaboration or using our components for other emulation projects.

Contact us at: info@interlisp.org