OCaml

[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] 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] 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

[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.

https://anil.recoil.org/notes/oxcaml-httpz

[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] 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