Interlisp was a software development environment developed at Xerox PARC in the 1970s and 1980s to support research in many areas including Artificial Intelligence, Graphical User Interfaces, and Computer Supported Collaborative Work using HyperText. The software has many versions as it evolved over 25 years.

The 1992 ACM Software System Award was awarded to the Interlisp system for

“… pioneering work in programming environments that integrated 

  • source-language debuggers,
  • fully compatible integrated interpreter/compiler, 
  • automatic change management,
  • structure-based editing,
  • logging facilities,
  • interactive graphics, and
  • analysis/profiling tools.”

Interlisp.Org is a project led by some of the original developers and users of the software, with help from Lisp and open source communities. They are working to restore and adapt the Medley version of Interlisp to modern computing infrastructure. The project will allow others to experience this seminal IDE (Integrated Development Environment) as well as a number of applications written in and for it.

The Interlisp.Org team is interested in how to preserve an idea and an experience through reviving and adapting it for the next generation. Exposing newcomers to the Interlisp software and inspiring experiences with it are central to the team’s preservation practice. They believe that saving the source code alone isn’t enough to preserve the software, and are working to revive Interlisp and adapt it to be useful in the modern world.

Interlisp’s goals in supporting the Software Preservation Network include:

  • Support researchers studying the history of software development paradigms, graphical user interfaces, hypertext, AI and other software methods
  • Build a case study for preservation of source code, algorithms, and software history
  • Invite Software Preservation Network members to participate in the revival of Interlisp

As an Implementation Sponsor of Software Preservation Network, Interlisp.Org’s support helps ensure that SPN continues to advance field level capacity for software preservation through community engagement, infrastructure support, and knowledge generation. We are grateful for Interlisp.Org’s contribution and its efforts to preserve an essential piece of software heritage. You can read more about Interlisp and even test an in-progress rebuild of the Medley Interlisp software here: https://interlisp.org/