The next OUPS meetup will take place on Tuesday, 3rd of November 2026. It will start at 6:30pm at the 4 place Jussieu in Paris. It will be in the in the amphitheater 45A. There is a map of the buildings.
Please, register on meetup as soon as possible to let us know how many pizza we should order.
For more details, you may check the OUPS’ website .
Moreover, we’d like to announce that the organizing team moved to the OCaml Zulip. Feel free to contact us there if you’d like to suggest talks.
This time we’ll have the following talks:
Compiling FFI-heavy OCaml to WebAssembly: An Experience Report on MOPSA – Réda Boudrouss
Abstract
Large OCaml applications often rely on native C and C++ libraries through the OCaml FFI, making them difficult to run in the browser. Existing browser backends compile OCaml to JavaScript or WebAssembly, but leave the native dependency stack behind.
In this presentation, we explore a different approach: compiling the OCaml runtime together with the complete native dependency stack to WebAssembly using Emscripten, and running the original OCaml bytecode on top of it. FFI calls are resolved through a static primitive table, without modifying existing FFI code or CamlIDL-generated bindings.
We demonstrate this approach on MOPSA, a static analyzer combining OCaml with LLVM/Clang, GMP, MPFR, Apron, and CamlIDL, and show how the complete application can run directly in a web browser.
Designing a Set-Theoretic Type Library in OCaml – Mickaël Laurent
Abstract
In this talk, I will share my experience using OCaml to design a library for set-theoretic types.
Set-theoretic types are difficult to define because they consist of several recursive components and layers.
Furthermore, the termination of certain operations on recursive types depends on a hash-consing system operating at various levels.
I will discuss the challenges and advantages of using OCaml, such as the difficulty of making some recursive modules typecheck and how we used algebraic effects to implement our hash-consing system.
After the talks there will be some pizzas offered by the OCaml Software Foundation and later on we’ll move to a pub nearby as usual.