Stack is a tool to build projects and manage their dependencies for the programming language Haskell. It uses the Cabal library but with a curated version of the Hackage software repository named Stackage.
Stack competes against Cabal's binary file cabal-install and has been created as a result of the overall criticism about dependency problems. However, it does not provide its own package format, but uses extant *.cabal files and complements projects with an added stack.yaml file.