Bertrand Meyer's technology+ blog
Software engineering, programming methodology, languages, verification, general technology, publication culture, and more
Société pour la Défense de l’Imparfait du Subjonctif (SDIS) Compte-rendu de l’assemblée annuelle 2025, 1er décembre 2025. Présents : Président, Secrétaire, Premier et Second vice-présidents, Trésorier, représentant des adhérents. Le Secrétaire (Bertrand Meyer) ouvre la séance à 17 heures et souhaite la bienvenue à tous les participants. La séance se poursuit avec le rapport du … Read more
[This note was first published in my newsletter (23 November 2025. One can subscribe to the newsletter here.] I might sound like a broken record, but the CloudFlare outage is one more example of the consequences of the software industry making the wrong technical choices. Where were the contracts? Rust, by all accounts the language … Read more
(A version of this note was published as three separate articles in the Communications of the ACM blog.) Work in engineering, science or technology can only be effective if it relies on precisely defined concepts. For the fundamental notions taught at school, particularly in mathematics, physics, and chemistry, the definitions, honed over centuries, have become … Read more
The news is so bad right now everywhere that it is natural to take refuge in discussing matters of (bad) style. I have things to say about the real issues too but not this time. I am following in the tradition of Niklaus Wirth who told me that he regularly sent letters of complaint to … Read more
New article: “Do AI models help produce verified bug fixes?” (Huang Li, Ilgiz Mustafin, Marco Piccioni, Alessandro Schena, Reto Weber and Bertrand Meyer), submitted for publication, preprint available on arXiv. Automatic Program Repair (APR) involves four steps: Locating the bug. Producing candidate corrections. Validating them (to make sure that they do correct the problem). Selecting the … Read more
A Google search for something entirely unrelated led me to a very old issue of the Daily Nexus, the student newspaper of the University of California, Santa Barbara, where I was teaching back then. Apparently (I had forgotten all about it of course) I was piqued by a student’s letter to the editor, where he … Read more
Bertrand Meyer: Obituary for Niklaus Wirth, in Formal Aspects of Computing, volume 37, issue 2, pages 1-11, published 3 March 2025, available here (publisher’s site). Shortly after Niklaus Wirth — Turing Award winner for his many seminal contributions including Pascal, Algol W, Modula, virtual machines, Lilith/Ceres, railway diagrams, PL/360, seminal textbooks… — passed away last … Read more
Li Huang, Sophie Ebersold, Alexander Kogtenkov, Bertrand Meyer and Yinling Liu, Lessons from Formally Verified Deployed Software Systems, submitted for publication (since March 2023), preprint available here for the full version (with detailed review of all 32 projects) and here for a shorter one (with same core content but only 11 detailed reviews, the others … Read more
Maria Naumcheva, Sophie Ebersold, Jean-Michel Bruel and Bertrand Meyer, UOOR: Seamless and Traceable Requirements, submitted for publication, February 2025, preprint available on arXiv. This article grew out of Maria Naumcheva’s PhD thesis defended on December 18 at the University of Toulouse (I will write separately about the thesis as a whole). It is part of … Read more
Li Huang, Bertrand Meyer and Reto Weber, New preprint: Loop unrolling: formal definition and application to testing, February 2025, submitted to publication. Available here on arXiv and also here. Abstract Testing coverage criteria usually make a gross simplification: they assume that loops will have their bodies executed 0 or 1 time. How much (specificall,y how … Read more