Remembering Maarten van Emden

Maarten van Emden died on January 4, 2023, at the age of 85.[1] He was a pioneer of logic programming, a field he explored for much of his career. I was not in his field, and only got to know him starting in 2010, so this is a personal, but not professional, remembrance of a very dear friend.

Maarten van Emden, 26 February 2011

His life

Maarten was born in Velp, the Netherlands, but his family soon moved to the Dutch East Indies, where his botanist father worked on improving tea plants. In 1942 the Japanese invaded. Maarten’s father escaped to join the resistance, but Maarten, his younger sister, and his mother were sent to a detention camp. As the war came to a close, his father was able to rescue and reunite the family. Over the next few years they returned to the Netherlands, with a brief return to the newly-formed Indonesia, followed by boarding school in Australia for Maarten. They were finally reunited in the Netherlands in 1954, where Maarten began his final year of high school. After graduating in 1955, he went to national flight school (Rijksluchtvaartschool). He did a year of military service, including flight training, and then joined KLM Royal Dutch Airlines. But KLM was adopting DC-8 jets for transatlantic service, whose speed, capacity, and ease of operation led to the need for fewer pilots. Maarten took advantage of a company program to enroll part-time in an engineering curriculum at the University of Delph. Later he was laid off by KLM and finished a master’s degree as a full-time student. He then enrolled in the PhD program administered by the University of Amsterdam with research at the Mathematisch Centrum (now CWI), and also made several visits to the University of Edinburgh. His 1971 dissertation was An Analysis of Complexity and his advisor was Adriaan van Wijngaarden. Maarten was awarded a post-doctoral fellowship by IBM, which he spent at the Thomas J. Watson Research Center in Yorktown Heights, NY during the 1971-1972 academic year, before returning to Edinburgh for a research position under Donald Michie in the Department of Machine Intelligence.  In 1975 he accepted a professorship at the University of Waterloo, and in 1987 he moved to the University of Victoria.

Programming

Maarten was one of 15 individuals recognized as Founders of Logic Programming by the Association for Logic Programming.[2] His work began with an early collaboration with Bob Kowalski[3] and continued throughout his career with collaborations and individual projects to explore many aspects of the field. Underlying his interest in logic programming was a fascination with programming and programming languages of all sorts.[4] His first language was Algol 60, which he taught himself using McCracken’s new book[5] when his university suddenly switched from Marchant calculators to a Telefunken TR-4 computer for the numerical methods course.[6] Moving on to the MC he was surrounded by ALGOL experts (his advisor van Wijngaarden was a member of the ALGOL 60 Committee and the instigator of the infamous ALGOL 68). Maarten was originally attracted to Edinburgh after hearing about the POP-2 timesharing system of Burstall and Popplestone; it was only later that he realized he’d initially used POP-2 as if it was ALGOL rather than a rich functional programming language. During his post-doc at IBM he learned APL and Lisp. Fred Blair was implementing a statically-scoped Lisp for the SCRATCHPAD computer algebra group.[7] And William Burge, who had worked with Burstall and Landin, was spreading the gospel of functional programming.[8] Ensconced in Edinburgh in 1972, he became an early convert to Kowalski’s logic programming, which he noted could be traced back as early as Cordell Green’s paper at the 4th Machine Intelligence workshop.[9] But Maarten’s first impression of Preliminary Prolog was not positive — the frequent control annotations seemed to detract from the logic. Nevertheless, he and Kowalksi began writing short programs to explore the ideas. And when David Warren returned from a visit to Marseille with a box of cards containing Final Prolog as well as his short but powerful WARPLAN program, things changed. The language no longer needed the control annotations, and Warren quickly ported its Fortran-coded lowest layer to the local DEC-10. WARPLAN served as a tutorial for all sorts of programs in the new language. He was surprised his friend Alan Robinson, the inventor of resolution logic, wouldn’t give up Lisp for logic programming.[10] At Waterloo, he advised Grant Roberts, who built Waterloo Prolog for the IBM System /370, and another series of students who built  several Prologs for Unix. At Victoria, he wrote a first-year textbook for science and engineering students based on C:

It is indeed true that object-oriented programming represents a great advance. It is also true that polymorphism is object-oriented programming does away with many if-statements and switch statements; that iterators replace or simplify many loops. But experience has shown that introducing objects first does not lead to a first course that produces better programmers; on the contrary. It is as much necessary as in the old days to make sure that students master variables, functions, branches, loops, arrays, and structures.

[11], page xi

In the acknowledgements of the book, he wrote:

I had the good fortune to grow up in three distinctive programming cultures: the Mathematical Centre in Amsterdam, the Lisp group in the IBM T.J. Watson Research Center, and the Department of Machine Intelligence in the University of Edinburgh. Though all of these entities have ceased to exist, I trust I am not the only surviving beneficiary.

If this book is better than others, it is due to my choice of those who were, often without knowing it, my teachers: H. Abelson, J. Bentley, W. Burge, R. Burstall, M. Cheng, A. Colmerauer, T. Dekker, E. Dijkstra, D. Gries, C. Hoare, D. Hoffman, N. Horspool, B. Kernighan, D. Knuth, R. O’Keefe, P. Plauger, R. Popplestone, F. Roberts, G. Sussman, A. van Wijngaarden, N. Wirth.

[11], page xi

Getting to know Maarten

As different as we were, Maarten and I had a few things in common: fathers who piloted B-24 bombers in WWII, a charismatic mutual friend named Jim Gray, attendance at the 1973 NATO Summer School on Structured Programming, books named Elements of Programming, and a fascination with the early development of programming languages. Jim Gray had been an informal mentor for me at UC Berkeley as I worked on CAL Snobol and Cal TSS. Then he left Berkeley for IBM Research in Yorktown, and made friends with Maarten. Jim soon decided he couldn’t tolerate life on the east coast, but before leaving he made Maarten and his wife Jos promise to drive across the country and visit him in California, where he would show them around. They took him up on the offer, and during a brief stay in fall 1972 at Jim’s home in Berkeley I met Maarten, but didn’t make much of an impression on him (although he later told me Jim had told him about the “great programmers on Cal TSS”). The next summer both Maarten and I attended the NATO Summer School on Structured Programming at Marktoberdorf, but neither of us remembered encountering the other. Maarten mentioned the summer school in his remembrance of Dijkstra.[12]

In 1974 I caught up with Jim Gray again, joining IBM Research in San Jose (before Almaden). The next summer Maarten visited Jim, although I didn’t learn of it until much later:

“After I returned to Europe Jim and I kept writing letters. In the summer of 1975 I was in a workshop in Santa Cruz and Jim came up in a beautiful old Porsche.  I was at the height of my logic programming infatuation. Jim was rather dismissive of it. Nothing of what he told me about System R  turned me on; the relationship died with that meeting. How I wish I could talk to him now about the mathematics of RDBs, which I started working on recently.”

[Maarten van Emden, personal communication, September 3, 2010]

Maarten apparently left three technical reports with Jim, who passed them along to me.[13] [14] [15] I looked at them, and then put them aside for the next 35 years. In the fall of 2010 I had retired and was spending more time on software history projects. I’d been following Maarten’s blog; a recent pair of articles about the Fifth Generation Computer System project and the languages Prolog and Lisp[16] [17] prompted me to contact him about a project I was contemplating: an historical archive of implementations of Prolog.[18] That began a friendship carried out mostly through some 2000 emails and almost 400 weekly video calls, plus one in-person visit when Maarten visited the Bay Area in early 2011. I will always remember his charming manners, gentle humor, wide-ranging interests, and intriguing stories.

Acknowledgements

Thanks to Maarten’s daughter Eva van Emden for information about his life.

For more of his writing, see:

References

[1] Eva van Emden. Maarten van Emden Obituary. The Times Colonist, January 10, 2023. https://www.legacy.com/ca/obituaries/timescolonist/name/maarten-van-emden-obituary?pid=203621344
[2] ALP Awards. Association for Logic Programming. https://www.cs.nmsu.edu/ALP/the-association-for-logic-programming/alp-awards/
[3] M. H. van Emden and R. A. Kowalski. The Semantics of Predicate Logic as a Programming Language. Journal of the ACM, Vol. 23, No. 4, 1976, pp. 733-742. https://www.doc.ic.ac.uk/~rak/papers/kowalski-van_emden.pdf
[4] Maarten van Emden. The Early Days of Logic Programming: A Personal Perspective. Association for Logic Programming Newsletter, August 2006. https://dtai.cs.kuleuven.be/projects/ALP/newsletter/aug06/nav/articles/article4/article.html
[5] Daniel McCracken. A Guide to ALGOL Programming. John Wiley and Sons, 1962. https://archive.org/details/mccracken1962guide
[6] Maarten van Emden. On Finding a Discarded Copy of “A guide to Algol Programming.” 1993 email to Frank Ruskey. https://web.archive.org/web/20050906222954/http://csr.uvic.ca:80/~vanemden/other/guideAlgol.html
[7] J. H. Griesmer and R. D. Jenks. SCRATCHPAD/1: An interactive facility for symbolic mathematics. In Proceedings of the second ACM symposium on Symbolic and algebraic manipulation (SYMSAC ’71). Association for Computing Machinery, New York, NY, USA, 42–58. https://doi.org/10.1145/800204.806266
[8] William Burge. Recursive Programming Techniques. Addison-Wesley 1975. https://archive.org/details/recursiveprogram0000burg
[9] Cordell Green. Theorem-Proving by Resolution as a Basis for Question-Answering Systems. Machine Intelligence 4, Bernard Meltzer and Donald Michie, editors, Edinburgh University Press, Edinburgh, Scotland, 1969, pages 183–205. https://www.kestrel.edu/people/green/publications/theorem-proving.pdf
[10] Maarten van Emden. Interview with Alan Robinson, inventor of resolution logic. June 8, 2010. https://vanemden.wordpress.com/2010/06/08/interview-with-alan-robinson-inventor-of-resolution-logic/
[11] M. H. van Emden. Elements of Programming. Andromeda Research Associates, Ltd. Third edition, 2009, page ix. https://abazu.ca/4EOP/EOP.pdf
[12] Maarten van Emden. I remember Edsger Dijkstra (1930 – 2002). August 2008. https://vanemden.wordpress.com/2008/05/06/i-remember-edsger-dijkstra-1930-2002/
[13] Robert Kowalski. Predicate Logic as Programming Language. Department of Computational Logic, University of Edinburgh, Memo No. 70, November 1973. https://www.doc.ic.ac.uk/~rak/papers/IFIP74.pdf
[14] M. H. van Emden and R. A. Kowalski. The semantics of predicate logic as a programming language. School of Artificial Intelligence, University of Edinburgh, MIP-R-103, February 1974. https://www.doc.ic.ac.uk/~rak/papers/kowalski-van_emden.pdf
[15] M. H. van Emden. First-order predicate logic as a high-level program language. School of Artificial Intelligence, University of Edinburgh, MIP-R-106, May 1974. http://webhome.cs.uvic.ca/~vanemden/Publications/FOPLasHLPL.pdf
[16] Maarten van Emden. Who Killed Prolog? A Programmer’s Place blog, August 21, 2010. https://vanemden.wordpress.com/2010/08/21/who-killed-prolog/
[17] Maarten van Emden. The Fatal Choice. A Programmer’s Place blog, August 31, 2010. https://vanemden.wordpress.com/2010/08/31/the-fatal-choice/
[18] Paul McJones, editor. Prolog and Logic Programming Historical Sources Archive. https://www.softwarepreservation.org/projects/prolog/

The Year of Prolog (1972-2022)

Prolog 50 1972-2022

50 years ago Alain Colmerauer and his colleagues were working on Prolog 0:

“A draconian decision was made: at the cost of incompleteness, we chose linear resolution with unification only between the heads of clauses. Without knowing it, we had discovered the strategy that is complete when only Horn clauses are used.”

[Colmerauer and Roussel, 2006]

With this system, and the idea of “metamorphosis grammars” (a generalization of what later became known as “definite clause grammars”), the team was able to implement a natural language man-machine communication system. The following year, the team released Prolog 1, the classic Marseille Prolog that quickly spread to Edinburgh, Leuven, Warsaw, Budapest, London, Waterloo, and beyond.

Now the friends of Alain Colmerauer are calling for 2022 to be “The Year of Prolog”. They’re marking the 50th anniversary with:

  1. An Alain COLMERAUER Prize awarded by an international jury for the most significant achievement in Prolog technology.
  2. A “Prolog School Bus” that will travel to reintroduce declarative programming concepts to the younger generation. This is a long-term initiative that will be initiated during the year. The purpose of this “Tour de France” (and elsewhere) will be to familiarize schoolchildren with Prolog, as they are already familiar with the Scratch language. At the end of this school caravan, a prize will be awarded to the ‘nicest’ Prolog program written by a student.

For more information, see:

A documentary about Alain Colmerauer

Alain Colmerauer – photo from his web site http://alain.colmerauer.free.fr

It’s called An idea crazy enough…..Artificial Intelligence and it’s being developed by Colmerauer‘s friends at Prolog Heritage via a crowd-funded project at Ulele.

Colmerauer died 12 May 2017; the hoped-for tribute this fall has evolved:

The project is a film to portray Alain Colmerauer’s life and work – his contribution to Logic Programming and Constraints Logic Programming – all brought to life through interviews with some of the key participants of his time, complemented by images and documents from the archives. In fact that was the best solution to invite witnesses in this period of sanitary difficulties.

Alain Colmerauer documentary, Ulule

A 20 Euro contribution gets you an invitation to an exclusive preview of the film online; a 50 Euro contribution gets you the invitation, your name in the credits as a donor, and a digital version of the documentary.

Colmerauer’s web site: http://alain.colmerauer.free.fr

Prolog Heritage: http://www.prolog-heritage.org

Prolog and Logic Programming Historical Sources Archive: http://www.softwarepreservation.org/projects/prolog/

Liz Bond Crews; Desktop Publishing Meeting

May 2017 Desktop Publishing Pioneers meeting, Computer History Museum. Liz Bond Crews is third from left in the front row. © Douglas Fairbairn Photography; courtesy of the Computer History Museum

On May 22 and 23, 2017, the Computer History Museum held a two-day meeting with more than 15 pioneering participants involved in the creation of the desktop publishing industry. There were a series of moderated group sessions and one-on-one oral histories of some of the participants, all of which were video recorded and transcribed.

Building on this meeting, three special issues of the IEEE Annals of the History of Computing were published, telling the stories of people, technologies, companies, and industries — far too much for me to cover here, so I will provide these links:

Last but not least, I had the pleasure of interviewing Liz Bond Crews, who worked first at Xerox and then Adobe to forge relationships and understanding between the purveyors of new technology (laser printers and PostScript) and the type designers, typographers, and designers who adopted that technology. An edited version of that interview appears in the third special issue of Annals:

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 dblp.org, the proceedings of the first two International Logic Programming Conferences are not available online, and according to worldcat.org, 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.

References

  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.] http://www.softwarepreservation.org/projects/prolog/lisbon/lpn/
  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. http://www.softwarepreservation.org/projects/prolog/lisbon/lpw83/ and https://dblp.org/db/conf/iclp/lpw1983.html
  3. Donald Knuth. Let’s not dumb down the history of computer science. Kailath Lecture, Stanford University, May 7, 2014. https://engineering.stanford.edu/donald-knuth-2014-kailath-lecture
  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. https://doi.ieeecomputersociety.org/10.1109/MAHC.2006.78
  5. Roberto Di Cosmo, founder and CEO. Software Heritage. https://www.softwareheritage.org
  6. Paul McJones, editor. Prolog and Logic Programming Historical Sources Archive. http://www.softwarepreservation.org/projects/prolog/
  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. https://computerhistory.org
  9. The Software Heritage Acquisition Process (SWHAP). https://www.softwareheritage.org/swhap/

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

Authors’ Edition of Elements of Programming

Cover of the book Elements of Programming by Alexander Stepanov and Paul McJones
Elements of Programming by Alexander Stepanov and Paul McJones

After almost 10 years in print, Addison-Wesley elected to stop reprinting Elements of Programming and has returned the rights to us. We are releasing an “Authors’ Edition” in two versions:

1. A free PDF (download from here)

2. A trade paperback from our imprint, Semigroup Press (purchase here or at Amazon – US$14.20 in either case).

The text is unchanged from the previous printing, except for corrections for all errata reported to us.

Update 5/15/2020: Lulu seems to have dropped their discount feature, so the price is the same everywhere.

Update 11/6/2019: Added Amazon link.

GTL is a LISP 2 implementation

A few months after my article “The LISP 2 Project” was published, I learned from Paul Kimpel that the language GTL includes a “non-standard” version of LISP 2. GTL stands for Georgia Tech Language. It is an extension of the Burroughs B 5500 Algol language, and its implementation extends the Burroughs Algol compiler. There is a new data type, SYMBOL, whose value can be an atomic symbol, a number, or a dotted pair. There is a garbage collector, and a way to save and restore memory using the file system. GTL was designed by Martin Alexander at the Georgia Institute of Technology between 1968 and 1969. The source code is available as part of the Burroughs CUBE library, version 13, and the manual is available via bitsavers.org; see here for details.

The LISP 2 Project

“The LISP 2 Project” appears in the October-December 2017 issue of IEEE Annals of the History of Computing (open access).

I first heard about LISP 2 around 1971, from a 1966 conference paper included in the reading for a U.C. Berkeley seminar on advanced programming languages. The goal of LISP 2 was to combine the strengths of numerically-oriented languages such as ALGOL and FORTRAN with the symbolic capabilities of LISP. The paper described the language and its implementation at some length, but by 1971 it was pretty clear that LISP 2 had not caught on; instead, the original LISP 1.5 had spawned a variety of dialects such as BBN-LISP, MACLISP, and Stanford LISP 1.6.

In 2005 I began a project to archive LISP history  and kept encountering people who’d been involved with LISP 2, including Paul Abrahams, Jeff Barnett, Lowell Hawkinson, Michael Levin, Clark Weissman, Fred Blair, Warren Teitelman, and Danny Bobrow. By 2010 I had been able to scan LISP 2 documents and source code belonging to Barnett, Herbert Stoyan, and Clark Weissman. In 2012, after writing about Hawkinson and others in an extended blog post “Harold V. McIntosh and his students: Lisp escapes MIT,” I decided to try to tell the story of the LISP 2 project, where so many interesting people’s paths had crossed. My sources included original project documents as well as telephone and email interviews with participants, and several participants were kind enough to provide feedback on multiple drafts. I let the article sit in limbo for five years, but last year after I published another anecdote in the Annals, editor Dave Walden encouraged me to submit this one.

On December 28, 2017, as the article was about to go to press, Lowell Hawkinson died suddenly from an accident.

Lowell Hawkinson, 1943 – 2018

Lowell Hawkinson passed away at the age of 74 on December 28, 2017 as a result of an accident. Lowell was a pioneer in LISP implementation and artificial intelligence. He co-founded Gensym Corporation in 1986 and served as its CEO through 2006. This obituary gives more details of his life and accomplishments.

I first got in touch with Lowell in 2010 because of my interest in archiving LISP history. We exchanged emails (and had one phone conversation), and over the years I wrote several blog posts and a journal article about work involving him:

Although my interactions with Lowell were brief, his kindness and modesty were manifest. He will be deeply missed by his family and friends.

In Search of the Original Fortran Compiler

“In Search of the Original Fortran Compiler” appears in the April-June 2017 issue of IEEE Annals of the History of Computing. If that link doesn’t work, you can read my final submitted version here.

I wrote the article to chronicle the search I began in late 2003 to find the source code for the original FORTRAN compiler for the IBM 704. Much of the search was documented right here on this Dusty Decks blog, which I created in July 2004 as a sort of advertisement.

I’d like to thank Burt Grad for encouraging me to write the article. Burt is a friend who began working on computer software in 1954 and hasn’t stopped — for example, see here and here and here and here.

Miscellaneous Lisp updates

Recently I made some long-delayed updates to History of LISP.  In the Lisp I/1.5 for IBM 704, 709, 7090 section, I added links to the excellent work by Andru Livisi (here) and Dave Pitts (here) for running LISP on emulators.

In the Other Lisp 1.5 implementations, I added a mention of LISP 1.5 for IBM M44. The M44 was an experimental machine that served as a testbed for some of the earliest virtual machine research.

In the Other Lisps section I added Lisp 1.6 for IBM 1130 (Boston Latin School), which was the first Lisp of Guy L. Steele Jr., who went on to work on MacLisp, Scheme, NIL, Common Lisp, and Connection Machine Lisp.  I also added PDP-11 LISP (Massachusetts Institute of Technology), which was the first Lisp of Richard M. Stallman, who went on to work on MacLisp, Lisp Machine Lisp, and Emacs Lisp.

In the Embedded Lisps section I added XLISP.

I made various additions in other sections including Scheme and Common Lisp.

New Japanese edition of Elements of Programming

Second Japanese edition of Elements of Programming
Elements of Programming, second Japanese edition
The original Japanese translation of Elements of Programming went out of print. But Yoshiki Shibata, the translator, proposed to Tokyo Denki University Press that they publish a new edition, and they agreed. It is available via Amazon.jp, and joins the English, Russian, Chinese, and Korean editions.

We wrote a special preface for this edition:

To our Japanese readers:

We are very grateful to our publisher and our translator Yoshiki Shibata for this opportunity to address our Japanese readers.

This book is in the spirit of Japanese esthetics: it tries to say as much as possible in as few words as necessary. We could not reduce it to 17 sounds like a traditional haiku, but we were inspired with its minimalist approach. The book does not have much fat. We actually hope that it does not have any fat at all. We tried to make every word to matter.

We grew up when Japanese engineering was beginning to revolutionize the world with cars that did not break and television sets that never needed repairs. Our hope is that our approach to software will enable programmers to produce artifacts as solid as those products. Japanese engineers changed the experience of consumers from needing to know about cars, or, at least, knowing a good mechanic, to assuming that the vehicle always runs. We hope that the software industry will become as predictable as the automotive industry and software will be produced by competent engineers and not by inspired artist-programmers.

Our book is just a starting point; most work to industrialize software development is in the future. We hope that readers of this book will bring this future closer to reality.

We would like to thank Yoshiki Shibata not only for his very careful translation, but also for finding several mistakes in the original.

Harold V. McIntosh, 1929-2015

Update 5/21/2019: Genaro J. Martínez, Juan C. Seck-Tuoh-Mora, Sergio V. Chapa-Vergara, and Christian Lemaitre recently published a paper “Brief Notes and History [of] Computing in Mexico during 50 years” centered around McIntosh’s accomplishments. arXiv:1905.07527 [cs.GL] DOI

Update 3/31/2019: Here are photos from a November 2017 memorial held for McIntosh at the Faculty of Computer Science of the Institute of Science at Autonomous University of Puebla, Puebla, Mexico.

Update 1/5/2017: For more on McIntosh’s professional career, see these obituaries at Physics Today and Journal of Cellular Automata.

Harold V. McIntosh, 1929-2015Harold V. McIntosh died November 30, 2015 in Puebla, Mexico. He was an American mathematician who became interested in what is now known as computer algebra to solve problems in physics, leading to his early adoption of the programming language LISP and to his design of the languages CONVERT (in collaboration with Adolfo Guzmán) and REC. His early education and employment was in the United States, but he spent the last 50+ years in Mexico, and received a Ph.D. in Quantum Chemistry at the University of Uppsala in 1972.

McIntosh was born in Colorado in 1929, the oldest of four sons of Charles Roy and Lillian (Martin) McIntosh. He attended Brighton High School in Brighton, near Denver. In 1949 he received a Bachelor of Science in physics from the Colorado Agricultural and Mechanical College, and in 1952 he received a Master of Science in mathematics from Cornell University. He did further graduate studies at Cornell and Brandeis, but stopped before receiving a Ph.D. to take a job at the Aberdeen Proving Ground. Two years later, he moved to RIAS (Research Institute for Advanced Studies), a division of the Glenn L. Martin Company. Around 1962 he accepted a position in the Physics and Astronomy department and the Quantum Theory Project at the University of Florida. After two years at the University of Florida, McIntosh accepted an offer at CENAC (Centro Nacional de Calculo, Instituto Politecnico Nacional) in Mexico. Over the next years, McIntosh worked in various positions in Mexico at Instituto Politecnico Nacional, Instituto Nacional de Energía Nuclear, and, from 1975 on, Universidad Autónoma de Puebla.

McIntosh was widely regarded for his research, writing and teaching; for details, see Gerardo Cisneros-S.: “La computación en México y la influencia de H. V. McIntosh en su desarrollo” (PDF). He organized several special summer programs in the early 1960s that introduced a number of students to higher mathematics and computer programming (see here for example). He also had a lifelong interest in flexagons, which he shared with his students. A symposium in his honor was held a month before he died.

Other resources

Harold V. McIntosh: CELLULAR AUTOMATA MISCELLANEA. Web site at cinvestav.mx

1961 Annual report of RIAS. PDF at ubalt.edu

Paul McJones. The First International LISP Conference (1963). Dusty Decks blog, April 23, 2012

Paul McJones. Harold V. McIntosh and his students: Lisp escapes MIT. Dusty Decks blog, July 6, 2012

Paul McJones, editor. History of Lisp : Other Lisp 1.5 implementations : MBLISP. Online at softwarepreservation.org

Celebration of late Prof. Harold V. McIntosh achievements. Faculty of Computer Science of the Institute of Science at Autonomous University of Puebla, Puebla, Mexico, November 29, 2017. Online at uncomp.uwe.ac.uk

Acknowledgements

José Manuel Gómez Soto for notifying me of McIntosh’s death and supplying the link to this obituary; Robert Yates, Lowell Hawkinson, and Adolfo Guzmán Arenas for their contributions to “Harold V. McIntosh and his students: Lisp escapes MIT”; and Genaro Juarez Martinez for informing me about the memorial celebration.

L. Peter Deutsch’s PIVOT program verification system

L. Peter Deutsch in his office at Xerox PARC, around 1972.PIVOT, the program verification system written in BBN-Lisp by L. Peter Deutsch and described in his PhD thesis, “An interactive program verifier” is a recent addition to the Software Preservation Group web site.

Deutsch is a computer scientist who made important contributions to interactive implementations of Lisp and Smalltalk. While he was in high school, he implemented the first interactive Lisp interpreter, running on a DEC PDP-1 computer. While still in high school, he worked with Calvin Mooers on the design of TRAC, and implemented the language on a PDP-1 at BBN. Then Deutsch enrolled at the University of California at Berkeley, where he soon joined Project Genie, one of the earliest timesharing systems. Meanwhile, at BBN, Deutsch’s original PDP-1 Lisp became the “conceptual predecessor” of BBN-Lisp, running first on the PDP-1, then the SDS-940 (running the Project Genie timesharing system), and finally the PDP-10 running BBN’s own TENEX. After several of the BBN-Lisp creators, including Deutsch, moved to Xerox PARC, BBN-Lisp became INTERLISP. By this time, Deutsch had received his bachelor’s degree at Berkeley, and with other Project Genie alumni had co-founded Berkeley Computer Corporation, which built a large timeshared computer (the BCC-500) but then went bankrupt. While working at PARC, Deutsch also attended graduate school at Berkeley, carrying out the research on program verification that produced the PIVOT system.

Deutsch was kind enough to donate his only source listing of PIVOT to the Computer History Museum (Lot number X7485.2015), and to allow scans of the listing and his thesis to be posted on the SPG web site.

Oral history of Bjarne Stroustrup

Update 5/14/2015: Here is a short video that was made for the Fellow Award Ceremony.

Update 4/9/2015: A video of the interview is now available. It’s searchable via the synchronized transcript.

In February I had the honor of conducting an oral history of Bjarne Stroustrup for the Computer History Museum, on the occasion of his being one of three 2015 Fellow Awards Honorees (the other two being Evelyn Berezin and Charles Bachman).

Programming languages have emerged over the last fifty or so years as one of the most important tools allowing humans to convert computers from theoretical curiosities to the foundation of a new era. By inventing C++ and working tirelessly to evolve, implement, standardize, and propagate it, Bjarne has provided a foundation for software development across the gamut from systems to applications, embedded to desktop to server, commercial to scientific, across CPUs and operating systems.

C was the first systems programming language to successfully abstract the machine model of modern computers. It contained a simple but expressive set of built-in types and structuring methods (structs, arrays, and pointers) allowing efficient access to both the processor and the memory. C++ preserves C’s core model, but adds abstraction mechanisms allowing programmers to maintain efficiency and control while extending the set of types and structures.

While several of the individual ideas in C++ occurred in earlier research or programming languages, Bjarne has synthesized them into an industrial-strength language, making them available to production programmers in an coherent language. These ideas include type safety, abstract data types, inheritance, parametric polymorphism, exception handling, and more.

In addition to its synthesis of earlier paradigms, C++ pioneered a thorough and robust implementation of templates and overloading. This has enabled the field of generic programming to advance from early research to sufficient maturity for inclusion in the C++ standard library in the form of STL. Additional generic libraries for graphs, matrix algebra, image processing, and other areas are available from other sources such as Boost.

By combining efficiency and powerful abstraction mechanisms in a single language, and by achieving ubiquity across machines and operating systems, C++ has replaced a variety of more specialized languages such as C, Ada, Smalltalk, and even Fortran. Programmers need to learn fewer languages; platform providers need to invest in fewer compilers. Even newer languages such as Java and C# are clearly influenced by the design of C++.

C++ has been the major focus of Bjarne’s career, and he has had unprecedented success at incremental development of C++, keeping it stable enough for use by real programmers while gradually evolving the language to serve the broadest possible audience. As he evolved the language, Bjarne took on many additional roles in order to make C++ successful: author (books, papers, articles, lectures, and more), teacher, standardization leader, and marketing person.

Bjarne started working on C with Classes, a C++ precursor, in 1979; the first commercial release of C++ was in 1985; the first standard was in 1998, and a major revision was completed in 2011. C++ was mature enough by 1993 to be included in the second History of Programming Languages conference, and a follow-on paper focusing on standardization appeared in the third HOPL conference in 2007.

I hope you enjoy reading the oral history as much as I did interviewing Bjarne.

See also: C++ Historical Sources Archive, Dusty Decks, 11 June 2007.

Update 1/30/2016: Updated URL for C from http://cm.bell-labs.com/cm/cs/cbook/index.html to https://9p.io/cm/cs/cbook/index.html.

Xerox Alto file server archive

McJones_office_1980
In 1980, Paul McJones used this Alto to develop portions of the Xerox Star operating system.

It’s been almost a year since I posted to this blog, but I haven’t been completely inactive. This week, as part of its Software Gems: The Computer History Museum Historical Source Code Series, the Computer History Museum released a set of files archived in the 1970s and early 1980s from the Xerox Alto file servers at Xerox PARC. The files include source code, executables, documents, fonts, and other files.

This release has been a long time in the making. The files were originally archived to 9-track magnetic tape, but around 1991 they were transferred to 8mm tape cartridges. Around 2003, before he joined the Computer History Museum, Al Kossow, working under a Nondisclosure Agreement with PARC, transferred the 8mm tapes to DVDs, and sifted through the entire archive looking for files specifically related to the Alto — the archive had included files from many other projects over several decades. After many years of discussion, and the involvement of a number of people inside and outside of PARC, an agreement with CHM was finally signed in February 2011, and a CD with the Alto files that Al had located was given to CHM.

In August of 2013, I asked Len Shustek what had become of the files, and he suggested I write a blog post about them. So I talked to Al (now CHM software curator), who gave me a copy of the files. It turns out they were images of the tape records written by a Cedar Mesa program called the Archivist. Luckily, when the 9-track tapes were transferred to 8mm tapes, a file called rosetta.tar containing the Archivist source code plus some documentation was included on each tape. Once I obtained a copy of rosetta.tar I was able to write a program that “dearchived” the tape records, recreating a set of file directories. To make the files easier to view over the web, I added code to create a static web site allowing the files to be browsed, including translations from Bravo format to HTML and Press format to PDF. (Bravo was the first WYSIWYG word processor, and Press was a device-independent print-file format.)

There are 14680 files in all, of which 8598 are distinct. They include the Alto operating system; BCPL, Mesa, and (portions of the) Smalltalk programming environments; applications such as Bravo, Draw, and the Laurel email client; fonts and printing software (PARC had the first laser printers); and server software (including the IFS file server and the Grapevine distributed mail and name server).

Although not many people ever used an Alto, it had a huge influence on the hardware and software we use today, so I am very pleased that this software is now available for study.

The blog post Len invited me to write is here. The archive itself is here, but I recommend starting with this walk-through of the archive describing what is there and who wrote the various programs. More detail about the archive (provenance, naming conventions, file types, etc.) is available here.

Dr. John E. L. Peck, 1918-2013

Dr. John E. L. Peck (1918-2013)
Dr. John E. L. Peck (1918-2013)
Dr. John E. L. Peck, whose work on ALGOL 68 was described in a recent post, passed away on November 6, 2013. His family has provided this obituary:

John, born August 14, 1918 in Pietermaritzburg, South Africa, passed away peacefully with his family by his side on November 6, 2013. He is predeceased by his wife Dornacilla of 61 years, and lovingly remembered by his sons, Edward (Phyllis) and Nigel (Susan); his twin daughters Lenny (George) and Gwenda; his sister Gwenyth; grandchildren Justin (Kristina), Linstead (Randi), Shannon, Tanya and Vernon; great-grandson Isaac; nieces and nephews, Elizabeth, Brian, Richard, Louise, Deborah, Sheryl, Ross, Janene, Randa, Dahl and Fraser; relatives, good friends and colleagues from around the world. John was the first Head of the University of Calgary Mathematics Dept. and founded UBC’s Department of Computer Science – his contributions to computer science were significant internationally. He was a key member of the international community that pioneered the field of Computer Science beginning in the early 60s. He was an avid outdoorsman who enjoyed alpine climbing, skiing and cycle touring. He also had a strong love of music playing pipe organ, piano and classical recorder. He enjoyed a full and rich life and will be greatly missed. A Celebration of his Life will be held Saturday, December 7, 2013 at 10:00am at Victory Memorial Park Funeral Centre, 14831 28th Avenue, Surrey, BC. In lieu of flowers, please consider making a donation to the charity of your choice.

Condolences may be offered at www.victoryfuneralcentre.ca

ALGOL 68: Implementation and more

John E. L. Peck joined the ALGOL 68 design project in 1966, was a coauthor of the report, edited the proceedings of the 1970 Munich implementation conference, hosted meetings that laid the foundations for the revised report, and chaired IFIP Working Group 2.1 from 1975 to 1978. Recently his son Edward Peck contacted me to say that he had come across a set of ALGOL 68-related documents in his father’s papers, and wondered if they would be appropriate for the ALGOL 68 section of the History of ALGOL web site. That led to some valuable additions:

I’d like to thank Edward Peck very much for making these documents available and for careful work scanning them.

Korean edition of Elements of Programming

In addition to the English, Korean edition of Elements of Programming Japanese, Russian, and Chinese editions, Elements of Programming is now available in a Korean edition published by Pearson Education Korea and available from Kyobo Book Centre. Five editions, five scripts.

P.S. I can’t find a listing for the book at www.pearson.co.kr; I will update this post and our book website if I hear of one.