We introduce the Ortac/QCheck-STM, a tool to automatically generate QCheck-STM tests based on Gospel specification, in a tutorial-like manner.

* OCaml Users and Developers Workshop 2025 // Singapore, Singapore // Oct 17, 2025

YouTube video by Jane Street

Ahrefs built the world's third-largest web crawler using OCaml, indexing petabytes of web data with a lean, efficient team.

Timéo shares his project integrating new refactoring features into Merlin, improving user experience with a new command.

Timéo shares his project integrating new refactoring features into Merlin, improving user experience with a new command.

* Introduction to the Dune build system, by OCamlPro * memprof-limits (first official release): Memory limits, allocation limits, and thread cancellation, with interrupt-safe resources * mlfront-shell - reference implementation of a build system * Zanuda -- OCaml linter experiment * YOCaml, a framework for static site generator * Lwt.6.0.0~beta (direct-style, multi-domain parallelism) * schm-ocaml * detri cmd * seven ocaml tutorials * Ortac/Wrapper: a new plugin for specification driven unit testing * Other OCaml News

WebAssembly (abbreviated Wasm) is a binary instruction format for a stack-based virtual machine. Wasm is designed as a portable compilation target for programming languages, enabling deployment on the...

I’m excited to share that the OCaml community has secured funding for the next round of Outreachy. Thanks to Jane Street and Tarides, we have funding for 3 mentees in the next cohort of Outreachy inte...

Implemented a production-minded database migration system for Chaufr: CLI, tracking, checksum validation, rollback, and safe SQL execution.

* OCaml Users and Developers Workshop 2025 // Singapore, Singapore // Oct 17, 2025

FUN OCaml is an open source conference and hacking event dedicated to OCaml enthusiasts and professionals around the globe! Here we publish recordings of the conference talks!

Emacs Integration for OCaml LSP Server: Introducing ocaml-eglot TL;DR ocaml-eglot provides full OCaml language support in Emacs through the Language Server Protocol (LSP) instead of direct Merlin integration. It offers the same features as merlin.el with simplified setup and enhanced capabilities like project-wide search. If you're starting fresh or want a more standardized approach, try ocaml-eglot, which is actively maintained. If your current merlin.el setup works well, you can continue using it. Quick start: Install ocaml-lsp-server, add ocaml-eglot to your Emacs config, and get the same OCaml development experience with less configuration. What is ocaml-eglot? ocaml-eglot connects Emacs to ocaml-lsp-server using the Language Server Protocol, providing a standardized way to get OCaml language support. Since the recent versions of Emacs (29), eglot, an LSP client, has been shipped with Emacs. However, merlin.el provides more features than LSP (which is designed to be generic), so relying solely on the features of LSP and eglot would limit functionality. Thus, we extended the LSP server to support more features, and ocaml-eglot allows you to benefit from these features in Emacs. ocaml-eglot is a minor mode. It therefore works in conjunction with a major mode to edit Caml code. Examples of major modes include tuareg, caml-mode and the recent neocaml. Who Should Use ocaml-eglot? Use ocaml-eglot if you: * Are starting fresh with OCaml * If you use or want to use Emacs * Want simplified configuration with automatic setup * Use multiple editors and want consistent OCaml support * Want access to project-wide search and rename features * Want to rely on an actively maintained project that evolves over time If your current setup is working perfectly and is heavily customised, merlin.el will still keep working, so there's no immediate need to migrate. However, for the moment, we don't plan to actively maintain merlin.el -- unless we receive a lot of requests. Getting Started Follow the installation instructions in the ocaml-eglot README. When migrating from merlin.el to ocaml-eglot, your existing keybindings should work immediately! Features Error Navigation: Quick jump to next/previous errors Type Information: Display types under cursor with adjustable verbosity, navigate enclosing expressions Code Generation: Pattern matching construction, case completion, wildcard refinement via "destruct" feature Navigation: Jump between language constructs (let, module, function, match), navigate phrases and pattern cases Search: Find definitions, declarations, and references For a detailed list of features, see the ocaml-eglot README. Next Steps * Try the basic setup with an existing OCaml project * Explore all the features of ocaml-eglot * Provide feedback at ocaml-eglot's GitHub Issues Documentation * ocaml-eglot README * OCaml.org editor setup tutorial Related Releases On January 17, 2025, ocaml-eglot version 1.0.0 was released, providing a new minor emacs mode to enable the editor features provided by ocaml-lsp-server. Subsequent releases 1.1.0 and 1.2.0 enable support for flycheck as a configurable alternative to flymake (1.0.0 release), Emacs 30.1 support, better user experience and error handling, as well as support for new features.

An overview of Jane Street's OxCaml branch introducing new extensions to OCaml, and how Tarides is supporting the project.

A detailed explanation of why I chose OCaml as the ‘default’ programming language for every project.

Discover our Internship project focusing on building new visualisations for OCaml's memory profiler "statmemprof".

YouTube video by Jane Street

Discover the work that went into improving OCaml debugging for macOS including frame pointers, CFI fixes and CI improvements.

Imandra leverages OCaml to develop automated reasoning tools that enable financial institutions to mathematically verify their trading algorithms meet regulatory requirements.

Watch media related to the OCaml programming language and ecosystem

For the past few months, I have been working on a project called CAMLBOY, a Game Boy emulator that runs in the browser.