Hackage

Hackage is the central package archive for the Haskell programming language. It hosts open-source libraries and tools and provides a public index of versioned packages, including metadata and source distributions. The repository serves as the primary source for Haskell packages that are consumed by the Cabal build system and related tooling.

Packages on Hackage include metadata such as name, version, synopsis, description, license, maintainer, category, and dependency information, along with the corresponding source tarballs. The package index used by Cabal and Cabal-install enables dependency resolution and automated fetching of required libraries during builds. The web interface at hackage.haskell.org offers browsing, search, and per-package pages, while a programmatic API and the package index enable automated tooling to discover and install packages.

Uploading and maintenance are handled by package authors and Hackage maintainers. Authors publish new versions via tools such as cabal-upload or through the web interface. Maintainers review submissions to ensure packaging quality and license compliance, and to manage access and visibility of packages. Hackage also provides security measures such as signing and transport protections to verify package integrity and authenticity.

History and ecosystem: Hackage emerged with the growth of the Cabal tooling and has become the default public repository for Haskell libraries. It coexists with Stackage, a separate service that provides curated, stable snapshots of a subset of packages for reproducible builds. Most Haskell tooling is configured to use Hackage as the primary package source, with Stackage serving as an optional alternative for stability-focused workflows.