Hpack is a format for Haskell packages. It is a modern alternative to the
Cabal package format and follows different design principles.

Hpack packages are described in a file named package.yaml. Both cabal2nix
and stack support package.yaml natively. For other build tools the hpack
executable can be used to generate a .cabal file from package.yaml.

Homepage:
http://hackage.haskell.org/package/hpack
