FUN OCaml schedule is now live on the website, and I put the link to the scheduled YouTube live stream there as well! fun-ocaml.com#schedule

Here is a rather lengthy write-up (in English) explaining why I chose #OCaml as my main programming language for my personal and professional projects! xvw.lol/en/articles/... I hope you find this interesting, and I welcome any feedback!

Looking forward to use this to improve the UX of using Irmin and MirageOS

Join Thibaut Mattio at FUN OCaml 2025 for "Build Language Models with Raven"! 📅 Sep 15-16, Warsaw 🇵🇱 Learn to build transformer models using OCaml & Raven's JAX-like ecosystem. We'll explore autodiff, attention mechanisms & leverage OCaml's type system for ML.

Fun with Include and Open in #OCaml to encode import schemas. A questionable use of the module language! xvw.lol/en/articles/...

A gem from Stephen Dolan, which proposes replacing the "generational hypothesis" that drives the design of generational GCs with a notion of lifetime dispersion as measured by the gini coefficient. Nice to see economics playing a role here! dl.acm.org/doi/pdf/10.1...

Something I predict will happen soon is using LLMs to port large test suites from one language / framework to another. Imagine starting a graphics or networking project and having hundreds of thousands of test cases already implemented!

Been having much fun over at @eeg.cl.cam.ac.uk and @tarides.com helping Jane Street with this release. Here's the online release party (starring multicore-the-fluffy-camel, our beloved mascot). Blog post incoming soon, but in the meanwhile, enjoy browsing oxcaml.org

I'm pleased to announce OxCaml! OxCaml is Jane Street's branch of OCaml. We've given it a new name and a snazzy logo, and done a bunch of work to make it easy for people to try.

Upcoming events on local-first: • Local-first Conf Berlin, Germany, 26–28 May www.localfirstconf.com – for industry folks • Workshop on Theory and Practice of Decentralized and Local-First Software, Bergen, Norway, 3 July 2025.ecoop.org/home/plf-pla... – for academics (industry crossover welcome)

👀 Oleg Kiselyov's compilers course in OCaml 👀 okmij.org/ftp/tagless-...

...and @dra27.uk successfully showed off the relocatable compiler to the core OCaml devs yesterday. It'll be awesomely useful to have this in the core toolchain when it comes to playing well with package managers. www.dra27.uk/blog/platfor...

A great new talk from Chris Casinghino, about making OCaml a better language for performance engineering. youtu.be/g3qd4zpm1LA?...

The 2nd Programming for the Planet workshop will be hybrid and co-located with ICFP/SPLASH in October in Singapore! Our call for papers is out at conf.researchr.org/home/icfp-sp..., submission deadline 3rd July 2025.

Initial idea - July 2019 Design proposal (before any code! 😇) - November 2019 Initial prototype - September 2021 Working prototype - September 2022 Candidate implementation - April 2025 #RAD 🫣

We just released OpenInfraQuote (oiq), an open source cost estimation tool built with OCaml. It runs in CI, reads Terraform plans and state files, and gives cost estimates from the CLI. No servers. More docs soon. We love building real tools in OCaml. github.com/terrateamio/... #ocaml #terraform

🐪 OpenInfraQuote (oiq) Malcolm just did a presentation on our new tool (oiq) from @terrateam.io for computing the cost of infrastructures. It's written in Ocaml and it's open source! github.com/terrateamio/...

Why are companies quietly using Elm, OCaml, and Haskell? Evan Czaplicki explores how typed functional languages offer competitive advantages to businesses like Jane Street & Standard Chartered, and how to evaluate their potential for your company.

Xavier van de Woystene presents on "Beyond the Basics of LSP: Advanced IDE services for OCaml" at #BOBkonf2025

And we're off! #BOBkonf2025 starts with Annette Bieniusa's keynote "Local-first Software".

If all goes well, OCaml 5 code will ride into space in < 24 hrs. www.dphispace.com/post/parsimo...

The keynote at @bobkonf.bsky.social is by Annette Bieniusa on “Local-first Software”.

Experimented with wasm_of_ocaml build for @rescript-lang.org compiler It gave almost 3x faster performance than the original js_of_ocaml build! 🔥

Finally - Relocatable OCaml in “fully relocatable” mode is also reproducible (as long as the C compiler is reproducible) and passes its testsuite 😮‍💨🥳🎉🍾🎊

This is a fun talk by our very own John Crepezzi, at the AI Engineering Summit. If you're interested in doing this kind of work, you should apply! www.youtube.com/watch?v=D7Bz...

Oooh Unikraft has been selected for GSoC again this year -- would be very fun to have someone get Zig+OCaml+MirageOS+Unikraft work so that we could cross-compile OCaml straight onto embedded devices again summerofcode.withgoogle.com/programs/202...

I took MirageOS's new "defunctorised" approach for a spin by upgrading VPNKit to the latest suite of MirageOS libraries. I wrote a little about the experience here. patrick.sirref.org/vpnkit-upgra...

Self-sufficiency can certainly be taken too far, and it would be inefficient for every country to try to build its own sovereign tech stack. But I do wonder how the new geopolitical reality may shape technology choices. Maybe local-first has a role to play in de-risking the use of US cloud services?

Is it possible to build a formally verified GC for OCaml that can be plugged into the compiler? We should how to in: "A Mechanically Verified GC for OCaml" kcsrk.info/papers/verif... This has been accepted to the Journal of Automated Reasoning. Code: github.com/prismlab/ver...

Got pretty far with Zig/OCaml cross compilation in a couple of hours of messing around. I can now build binaries for my rPi from my mac with a dune build thanks to @chrisarmstrong.link's work! github.com/chris-armstr... for WIP

The #OCaml community has signed up to Outreachy! Please do consider signing up to be a mentor, it's a lot of fun and a really great way to help grow the community :)) discuss.ocaml.org/t/outreachy-...

Just like we containerized webapps, we'll have to containerize AI agents... but how? What first principles led to containers in the first place, and how do they transpose to LLMs? This was my first talk at an AI meetup, but I doubt it will be the last! youtu.be/XWO_3My2eVU?...

"Automatically Verifying Replication-aware Linearizability" has been accepted to OOPSLA 25. Draft: kcsrk.info/papers/mrdtc... This work is a substantial improvement over our prior work (dl.acm.org/doi/10.1145/...) on verifying MRDTs.

New NetHSM 2 available now - after releasing NetHSM just over a year ago. NetHSM 2 offers more powerful hardware and therefore even better speed (over 50% faster). 😎 See the details here: www.nitrokey.com/news/2025/ne... #opensource

. @anil.recoil.org doing what he does best -- stitching together bleeding edge technologies into impressive stunts :-) anil.recoil.org/notes/bushel...

A post about the long and winding road that lead to the Dune build system for OCaml, and, eventually, to Dune replacing our old internal build system, Jenga. blog.janestreet.com/how-we-accid...

have you seen github.com/ocaml-multicore/saturn? it's a package that provides lock-free data structures for OCaml (and they are multicore-safe) do you have a project where this could be useful? I would love to chat

Chennai OCaml is meeting again, this time at IIT Madras. www.meetup.com/chennai-ocam...

Gosh, there's been a lot of positive activity in the OCaml community recently; here's a recap by @gazagnaire.org about what @tarides.com has been up to. discuss.ocaml.org/t/tarides-20...

2024 was a big year for OCaml! The team at @tarides.com with incredible support from the community, released the Dune Developer Preview, OCaml 5.3 multicore, WebAssembly boosts, full Windows support, and events like FUN OCaml, plus much more. Read more: tarides.com/blog/2025-01...

The paper on Data Race Freedom a la Mode was just awarded a Distinguished Paper award at POPL25! An excellent excuse to read all about a potential future for safe parallel programming in OCaml. richarde.dev/papers/2025/...

if you know a good place for a tech conference / hackathon, drop us a note needs: - room for ~120-200 people) - hangout area / lounge with desks / rooms (ideally private) - cozy - good wifi - live streaming possible (dedicated connection, can bring our own equipment) - possibility to stay open late

OCaml 5.3 has been released: discuss.ocaml.org/t/ocaml-5-3-... It brings syntax support for effect handlers. It also brings back statistical memory profiler and MSVC support.

OCaml 5.3.0 is out discuss.ocaml.org/t/ocaml-5-3-...! Thanks to the considerable efforts of my colleagues, it includes the restored MSVC port (the draft was my Christmas 2022 OCaml hacking). Hopefully 5.4.0 will conclude another 2021/22 bit of hacking with Relocatable OCaml and faster opam switches!

WARNING: This product contains programming languages known to the State of California to cause memory unsafety

Tarides has received funding to port OCaml libraries to Eio from NLNet under NGI0 Core: nlnet.nl/project/OCAM.... The project aims to develop tools to automatically rewrite code and identify potential issues during the transition from monadic to direct-style concurrency.

OCaml or Gleam! Both have excellent tracks on exercism.com, if you like puzzle-based learning

🚀 Ahrefs: OCaml at Web Scale 💻 Ahrefs, with just 120 people, uses OCaml to process 6B pages daily and power the 2nd largest web crawler after Google. Backed by a 475 PB SSD database, 4200 servers, and 660000 CPU cores, they showcase OCaml’s efficiency in massive-scale data processing. 👉 ahrefs.com