OCaml Packages

Explore thousands of open-source OCaml packages with their documentation

Publish a Package

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

opam

The OCaml Package Manager

Opam is a source-based package manager for OCaml. It supports multiple simultaneous compiler installations, flexible package constraints, and a Git-friendly development workflow

4956

Packages
37

New packages this month
91

Updates this week

packages

Most Used

odoc

OCaml Documentation Generator

Used by 1373 other packages

alcotest

Alcotest is a lightweight and colourful test framework

Used by 627 other packages

lwt

Promises and event-driven I/O

Used by 613 other packages

cmdliner

Declarative definition of command line interfaces for OCaml

Used by 419 other packages

fmt

OCaml Format pretty-printer combinators

Used by 370 other packages

New Packages

jsont

Declarative JSON data manipulation for OCaml

22 hours ago

bytesrw

Composable byte stream readers and writers for OCaml

2 days ago

areas-and-adversaries

TTRPG title generator

3 days ago

catala-format

A formatter for Catala based on the Topiary universal formatting engine

8 days ago

cohttp-bench

Benchmarks binaries for Cohttp

9 days ago

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 to specify the version constraints, so only compatible revisions are chosen for a build. It comes with a performant constraint solver, a flexible CLI, a well-specified metadata format, and an easy access to the package manager logic via OCaml libraries.

Package Stability

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

community

Start Contributing

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