Preserving (more of) the history of logic programming and Prolog

This is a preview of an article that later appeared in the Newsletter of the Association for Logic Programming. I posted it here first because of the infrequent publication schedule of that newsletter and my desire to announce a new website: Prolog and Logic Programming Historical Sources Archive.

Logic programming has a long and interesting history with a rich literature comprising newsletters, journals, monographs, and workshop and conference proceedings. Much of that literature is accessible online, at least to people with the appropriate subscriptions. And there are a number of logic programming systems being actively developed, many of which are released as open source software.

Unfortunately, the early years of logic programming are not as consistently preserved. For example, according to, the proceedings of the first two International Logic Programming Conferences are not available online, and according to, the closest library copies of the two are 1236 km. and 8850 km. away from my home in Silicon Valley. Early workshop proceedings and many technical reports are similarly hard to find (but see [1, 2]!). And the source code of the early systems, although at one time freely distributed from university to university, is now even more difficult to find.

As noted by people like Donald Knuth [3], Len Shustek [4], and Roberto Di Cosmo [5], software is a form of literature, and deserves to be preserved and studied in its original form: source code. Publications can provide overviews and algorithms, but ultimately the details are in the source code. About a year ago I began a project to collect and preserve primary and secondary source materials (including specifications, source code, manuals, and papers discussing design and implementation) from the history of logic programming, beginning with Marseille Prolog. This article is intended to bring awareness of the project to a larger circle than the few dozen people I’ve contacted so far. A web site with the materials I’ve found is available [6]. I would appreciate suggestions for additional material [7], especially for the early years (say up through the mid 1980s). The web site is hosted by the Computer History Museum [8], which welcomes donations of historic physical and digital artifacts. It’s also worth noting the Software Heritage Acquisition Process [9], a process designed by Software Heritage [5] in collaboration with the University of Pisa to curate and archive historic software source code.

Maarten van Emden provided the initial artifacts and introductions enabling me to begin this project. Luís Moniz Pereira provided enthusiastic support, scanned literature from the early 1980s [1, 2], and encouraged me to write this article. And a number of other people have generously contributed time and artifacts; they are listed in the Acknowledgements section of [6] as well as in individual entries of that web site.


  1. Luís Moniz Pereira, editor. Logic Programming Newsletter, Universidade Nova de Lisboa, Departamento de Informática. Issues #1-#5, 1981-1984. [Note that this newsletter was typeset, galley-proofed, and printed in color.]
  2. Luís Moniz Pereira, António Porto, Luís Monteiro, and Miguel Figueiras, editors. Proceedings of Logic Programming Workshop’83. Praia da Falésia, Algarve / PORTUGAL, 26 June – 1 July, 1983. Núcleo de Intelligência Artificial, Universidade Nova de Lisboa. and
  3. Donald Knuth. Let’s not dumb down the history of computer science. Kailath Lecture, Stanford University, May 7, 2014.
  4. Len Shustek. What Should We Collect to Preserve the History of Software? IEEE Annals of the History of Computing, Vol. 28, No. 4, October-December 2006.
  5. Roberto Di Cosmo, founder and CEO. Software Heritage.
  6. Paul McJones, editor. Prolog and Logic Programming Historical Sources Archive.
  7. Do you have a card deck or listing of the original Marseille interpreter? Or the source code for NIM IGÜSZI PROLOG, IC-Prolog, EMAS Prolog, or LogLisp, just to name a few?
  8. Computer History Museum. Mountain View, California.
  9. The Software Heritage Acquisition Process (SWHAP).

Update 1/21/2021: added the link to the article as published in the ALP Newsletter.

Update 5/5/2024: updated the link to the ALP Newsletter.