Since ELIZA was created by [Joseph Weizenbaum] in the 1960s, its success had led to many variations and ports being written over the intervening decades. The goal of the ELIZA Archaeology Project by Stanford, USC, Oxford and other university teams is to explore and uncover as much of this history as possible, starting with the original 1960s code. As noted in a recent blog post by [Anthony Hay], most of the intervening ‘ELIZA’ versions seem to have been more inspired by the original rather than accurate replicas or extensions of the original. This raises the question of what the original program really looked like, a question which wasn’t answered until 2020 when the original source code was rediscovered.
A common misconception about ELIZA was that it was written in Lisp, but it was actually written in MAD-SLIP, with MAD being an ALGOL 58-inspired language and SLIP (Symmetric LIst Processor) an extension library written by [Weizenbaum], first for Fortran and then for MAD and ALGOL. Ultimately the original code was found in the bowels of the MIT archives, which is now finally available for the world to see.
This version of ELIZA is from 1965 and predates the publication of [Weizenbaum]’s paper (PDF) in the January 1966 Communications of the ACM journal issue in which he details the workings of the code, as well as a partial listing. Thanks to some archive spelunking efforts, we can now once again see the full code as half a century of ELIZA history is being puzzled back together. Here project member [Jeff Shrager] would like to remind us that the team very much welcomes assistance from the community in this effort.
Thanks to [Jeff Shrager] for the tip, as well as his efforts on this archaeological project.
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.