OCaml Packages

Explore thousands of open-source OCaml packages with their documentation.

opam is the package manager for the OCaml ecosystem

opam is a source-based package manager for OCaml that supports multiple simultaneous compiler installations, flexible package constraints, and a Git-friendly development workflow.
It's been in use with the OCaml ecosystem since 2013 and is well maintained.

Installation / day
Update / week

Stable Ecosystem

Focus on your code, and opam takes care of distributing it

Our users have the highest standards for the OCaml ecosystem to run mission-critical applications across a variety of operating systems, and they expect that a package that compiles today will still work a decade from now.

Continuous Integration

Before any package update, we run sandboxed matrix builds for boundaries of the dependencies and for each of the dependent packages. A package publication will never break the rest of the ecosystem.

State of the art

opam supports publishing multiple versions of packages simultaneously, and to specify the version constraints to ensure that only compatible revisions are chosen for a build. It comes with a performant constraint solver, a flexible CLI, a well-specified metadata format, and easy access to the package manager logic via OCaml libraries.


The opam project and package repository is maintained by a team of developers who ensure that everything is not only running smoothly, but curated to maintain a high degree of metadata quality. This makes it one of the most stable package repositories available today.

Start contributing.

Learn how to publish your first opam package today and make it available to the rest of the community.

Learn how to contribute