Stackage

Stackage is a comprehensive package repository for the Haskell programming language. It serves as a curated collection of Haskell packages, designed to provide a stable and reliable environment for Haskell developers. The repository is maintained by the Haskell community and is intended to facilitate the use of Haskell packages by providing a consistent and well-tested set of dependencies.

Stackage is built on top of the Hackage package repository, which is the primary package repository for Haskell. However, Stackage takes a more conservative approach to package inclusion, focusing on stability and compatibility. This is achieved through a rigorous testing process, where each package is tested against a set of known-good dependencies to ensure compatibility.

Stackage is organized into "snapshots," which are point-in-time collections of packages that are known to work together. These snapshots are designed to provide a stable environment for Haskell projects, allowing developers to rely on a consistent set of dependencies. Snapshots are created on a regular basis, typically every few weeks, and are given a unique identifier that can be used to refer to a specific set of packages.

Stackage also provides tools for working with snapshots, including a command-line tool called "stack" that can be used to create and manage Haskell projects that use Stackage snapshots. The stack tool provides a number of features, including dependency resolution, package installation, and project building, making it a valuable tool for Haskell developers.

In summary, Stackage is a curated package repository for the Haskell programming language that provides a stable and reliable environment for Haskell developers. It is built on top of the Hackage package repository and is organized into snapshots that provide a consistent set of dependencies. Stackage also provides tools for working with snapshots, including the stack command-line tool.