Install opam with Homebrew, apk, apt, dnf, MacPorts, Nix, pacman, scoop, winget, zypper

Project links

• Homepage
• Repository
• Upstream docs
• Package manager page

Commands and aliases

• opam
• opam-installer

Project history

The opam history published by the project traces the work to OCamlPro and the wider OCaml community in 2012. Thomas Gazagnaire pushed the first public commit in February 2012; constraint-solving work from Roberto Di Cosmo and Pietro Abate helped connect opam with Mancoosi tools such as CUDF and dose; and documentation and website work followed before the public beta.

The first public beta appeared in January 2013, and opam 1.0.0 was announced on March 15, 2013. The 1.0 release added an auto-configuration tool around opam init, shell completion, toplevel script loading, and related setup tasks, which lowered the cost of getting a usable OCaml environment.

The project quickly became more than a package installer. It standardized switch-based OCaml compiler management, package descriptions, solver integration, and repository workflows in a language ecosystem where compiler versions and native dependencies often matter as much as library versions.

Adoption history

Mirage began using opam in June 2012 for custom compiler needs, and the opam-repository grew through community package submissions. Jane Street's Core libraries appeared in the repository in July 2012, Travis CI was integrated into pull-request processing in September 2013, and contributors were contacted in 2013 to relicense repository contributions to CC0 for the move to the ocaml organization.

The package metadata in this batch records opam across many OS package managers, including Alpine, Homebrew, Debian, Fedora, MacPorts, Nix, Arch, Scoop, Ubuntu, WinGet, and openSUSE. That broad packaging footprint reflects opam's role as the expected bootstrap tool for OCaml development across Unix, macOS, and Windows-oriented environments.

How it is used

Developers use opam to install OCaml compilers and libraries, create and switch between isolated compiler environments, update package metadata, upgrade installed packages, pin packages from local or remote sources, and reproduce project dependency sets. The homepage's basic workflow is list, install, update, and upgrade; day-to-day OCaml work adds switches and project-local package constraints.

Operators and distribution maintainers care about opam because it bridges source builds, solver constraints, compiler variants, and external system packages. A package can be available in opam while still depending on native libraries provided by Homebrew, apt, pacman, or another host package manager.

Why package nerds care

opam is one of the cleaner examples of a language package manager that also manages language runtimes. Its switch model makes compiler selection explicit, and its repository model gives OCaml packages machine-readable metadata while keeping the package index in Git.

For package nerds, opam is important because it makes the hard part visible: OCaml package installation is not just downloading archives, but solving constraints across compiler versions, library packages, build tools, and external dependencies. That is why opam sits naturally in both developer-tools and dependency-management categories.

Timeline

• 2012: early opam work began, with Mirage using opam in June and key repository packages arriving later that year.
• January 2013: the first public beta was released.
• March 15, 2013: opam 1.0.0 was announced.
• November 2013: opam 1.1.0 was released and Louis Gesbert became technical lead.
• 2013: opam-repository moved toward CC0 relicensing and the ocaml GitHub organization.

Related projects

• opam is closely tied to opam-repository, OCaml compiler switches, MirageOS, CUDF, dose, aspcud, and the OCaml Platform. It also interacts with host package managers because many OCaml packages depend on native libraries and tools outside the OCaml package universe.

Sources

• https://ocamlpro.com/blog/2013_01_17_beta_release_of_opam/
• https://opam.ocaml.org/
• https://opam.ocaml.org/about.html
• https://opam.ocaml.org/blog/opam-1-0-0-released/
• source_facts.config-file-location
• source_facts.executables
• source_facts.package-manager