mastodon 4.8.0-nightly.2026-10-06The industrial-strength functional programming language | safe, expressive, performant
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The OCaml Users Survey 2026 is now open! 📊
Share your experience with OCaml - from tools you use to new questions on AI/LLM tooling and debugging. Takes 10-15 minutes, open until May 25th.
https://forms.gle/gt5nikqUmoQWeYYQ9
https://discuss.ocaml.org/t/ann-ocaml-users-survey-2026/18026
[OCaml Planet AI] OxCaml SIMD intrinsics enable building performant ONNX inference engines in OCaml.
Details here: https://www.tunbury.org/2026/03/13/oxcaml-inference/
[OCaml Planet AI] Practical performance analysis: same algorithm, two implementations (OCaml and OxCaml). Direct comparison of assembly generation and execution speed.
Full analysis: https://www.tunbury.org/2026/03/14/pi-day/
[OCaml Planet] Building httpz: a high-performance HTTP/1.1 parser with zero heap allocation using OxCaml's unboxed types, local allocations, and mutable local variables.
The parser achieves zero allocation by leveraging OxCaml's unboxed types and local allocation features to avoid heap pressure during request parsing.
[OCaml Planet AI] Security notice: The signing key for apt.robur.coop has been re-signed. Action required for users of Robur's repository.
Full announcement: https://blog.robur.coop/articles/2026-03-13-apt-key-re-signed.html
[OCaml Planet AI] Thomas Gazagnaire visits satellite production facilities in LA. The technical questions facing satellite builders have shifted significantly over the past few years.
From Cannes to Los Angeles: https://gazagnaire.org/blog/2026-03-12-satellite-factories.html
[OCaml Planet AI] How do you efficiently serve millions of geospatial embedding tiles? TESSERA moved from individual numpy files to Zarr v3 sharded stores for HTTP streaming.
Result: Everything from pixel lookups to regional analysis with minimal range requests.
[Changelog] Release of OCaml 5.4.1 and 4.14.3: We have the pleasure of announcing the dual releases of OCaml 4.14.3 and OCaml 5.4.1, dedicated to the memory of Nicolaas Govert de Bruijn on the anniversary of his death.
Those releases are a collection of safe and valuable runtime bugfixes.
The OCaml 5.4.1 release also contains a fix for the -pack mode for macOs and various TSAN fixes.
More importantly, those new versions harden the Marshal module against malicious… https://ocaml.org/changelog/2026-02-17-ocaml-541-and-4143?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] Grants Available for Improving Security Across the OCaml Ecosystem: Building a more secure OCaml ecosystem is a community-wide effort, and now there's a major opportunity to get funded for it.
The OCaml Security Team, in partnership with the OCSF, has just announced a new Security Grant program with up to €100.000 available for projects that strengthen the OCaml ecosystem's security.
Whether your expertise is in building robust tooling, writing in-depth… https://ocaml.org/changelog/2025-10-03-ocaml-security-grants?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] Dune-release 2.2.0: We are excited to announce the release of dune-release 2.2.0 which brings full compatibility with cmdliner 2.0.0!
Please note that this release introduces a change in user-facing behavior: following the stricter requirements of Cmdliner 2.0, prefix-matching for command options is no longer supported. Users must now provide the full wording for all flags (for example, --skip-tests instead of --skip-test).
We recommend that all users… https://ocaml.org/changelog/2026-01-29-dune-release-220?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] Dune 3.21.1: The Dune team announces the release of dune 3.21.1.
This is a small patch release consisting of a few bug fixes. See the full changelog for all the changes.
If you encounter a problem with this release, please report it in our issue tracker. You can also leave comments on the discuss announcement. https://ocaml.org/changelog/2026-02-11-dune-3211?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] OCaml-LSP 1.25.0: This release of ocaml-lsp-server introduces support for .mlx files, new custom requests, and configuration updates for code-lens.
Features
* .mlx Support: Added support for .mlx files, including diagnostics, code actions, hover, and formatting via ocamlformat-mlx.
* New Custom Requests: Added typeExpression, locate, and phrase requests to the server.
* Code-Lens Configuration: code-lens for nested let bindings is now… https://ocaml.org/changelog/2025-12-20-ocaml-lsp-1250?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] 5.6.1-504: We're happy to announce the release of merlin v5.6.1-504!
This latest release brings performance optimizations, refined editor behavior, and improved stability to your OCaml development environment.
Key Improvements
* Smarter Signature Help: Now triggers correctly on unfinished let ... in bindings and no longer appears redundantly on function names.
* More Reliable Completion: Fixed issues with completion for inlined record labels.
*… https://ocaml.org/changelog/2025-12-20-merlin-v561-504?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] 4.7.1-413: We're happy to announce the release of merlin v4.7.1-413, which fixes an issue in the merlin binary that prevented installation! https://ocaml.org/changelog/2025-12-19-merlin-v471-413?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] 2.5.0: Hi everyone,
We’re happy to announce the release of opam 2.5.0 and encourage all users to upgrade.
Note: the following section will recap the various major changes in opam 2.5.0 for anyone who haven’t already read the previous pre-release announcements. For those who did, note that nothing changed between 2.5.0~beta1 and the final 2.5.0.
What’s new? Some highlights:
* Speedup opam update up to 70%. Thanks to @arozovyk, opam update now… https://ocaml.org/changelog/2025-11-27-opam-250?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] 2.7.1: We announce the release of opam-publish 2.7.1, whose full release notes can be seen here.
Changes in opam-publish 2.7.1
In 2.7.0, opam-publish changed the way user’s branches are pushed to their GitHub forks before opening a PR, switching from using SSH keys to using the GitHub API token that opam-publish already requires.
2.7.1 fixes a couple of bugs related to that where opam-publish stopped working if the GitHub Action workflow files of… https://ocaml.org/changelog/2025-11-18-opam-publish-271?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] 0.28.1: We're happy to announce the release of OCamlFormat 0.28.1!
Highlight
* * Support for OCaml 5.4
(#2717, #2720, #2732, #2733, #2735, @Julow, @Octachron, @cod1r, @EmileTrotignon)
OCamlformat now supports OCaml 5.4 syntax.
Module packing of the form ((module M) : (module S)) are no longer
rewritten to (module M : S) because these are now two different syntaxes.
* * Reduce indentation after |> map (fun (#2694, @EmileTrotignon)
Notably, the… https://ocaml.org/changelog/2025-10-24-ocamlformat-0281?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] Release 0.28.0: Note: Release was retracted in favor of 0.28.1. https://ocaml.org/changelog/2025-10-21-ocamlformat-0280?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] 0.37.0: We are pleased to announce the release of ppxlib 0.37.0. This version introduces initial support for the OCaml 5.4 compiler and provides several enhancements to AST handling and code generation.
Key Highlights
* OCaml 5.4 Support: This release includes initial support for OCaml 5.4.
* Module Derivers: Users can now derive code from module bindings and module declarations, expanding the scope of automated code generation.
* New Context-Free… https://ocaml.org/changelog/2025-10-10-ppxlib-0370?utm_source=dlvr.it&utm_medium=mastodon
[Changelog] 2.5.1: We're happy to announce the release of mdx 2.5.1, which brings support for OCaml 5.4, as well as improvements to the handling of skipped blocks in .mli/.mld files. https://ocaml.org/changelog/2025-10-08-mdx-251?utm_source=dlvr.it&utm_medium=mastodon
[Backstage OCaml] 3.21.0~alpha5: We're happy to announce the sixth alpha release of Dune! https://ocaml.org/backstage/2026-01-05-dune-3210alpha5?utm_source=dlvr.it&utm_medium=mastodon
[Backstage OCaml] 3.21.0~alpha4: we're happy to announce the fifth alpha release of Dune! https://ocaml.org/backstage/2025-12-15-dune-3210alpha4?utm_source=dlvr.it&utm_medium=mastodon
[Backstage OCaml] 3.21.0~alpha3: We're happy to announce the fourth alpha release of Dune! https://ocaml.org/backstage/2025-12-11-dune-3210alpha3?utm_source=dlvr.it&utm_medium=mastodon
[Backstage OCaml] 3.21.0~alpha2: We're happy to announce the third alpha release of Dune! https://ocaml.org/backstage/2025-12-08-dune-3210alpha2?utm_source=dlvr.it&utm_medium=mastodon
[Backstage OCaml] 3.21.0~alpha1: We're happy to announce the second alpha release of Dune! https://ocaml.org/backstage/2025-12-08-dune-3210alpha1?utm_source=dlvr.it&utm_medium=mastodon
[Backstage OCaml] 3.21.0~alpha0: We're happy to announce the first alpha release of Dune! https://ocaml.org/backstage/2025-12-08-dune-3210alpha0?utm_source=dlvr.it&utm_medium=mastodon
[OCaml Planet AI] Practical OCaml: building a fuel price finder. The UK Fuel Finder API provides real-time data from over 7,000 petrol stations nationwide.
[OCaml Planet AI] Full writeup available at:
https://www.tunbury.org/2026/03/13/fuel-prices/
OCaml Weekly News for March 17, 2026 aggregates the week's most important developments in the OCaml ecosystem. Catch up on what you missed: https://alan.petitepomme.net/cwn/2026.03.17.html
Stay informed about tooling updates, compiler improvements, and community projects.
[Changelog] opam 2.5.1: Feedback on this post is welcomed on Discuss!
We are pleased to announce the release of opam 2.5.1 fixing a security issue (OSEC-2026-03) and other minor things.
We advise everyone to upgrade. Please read on for installation and upgrade instructions.
Security fix
OSEC-2026-03: Invalidate .install fields containing destination filepath trying to escape their scope. Thanks to @andrew@mastodon.social for reporting this issue. (#6897)
Distributions… https://ocaml.org/changelog/2026-04-16-opam-2-5-1?utm_source=dlvr.it&utm_medium=mastodon