Difference between revisions of "Haskell Platform"

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* IRC channel: #ghc @ freenode.org
* IRC channel: #ghc @ freenode.org
* [http://www.galois.com/blog/2009/03/23/one-million-haskell-downloads/ Download statistics for Haskell Packages]
* [http://www.galois.com/blog/2009/03/23/one-million-haskell-downloads/ Download statistics for Haskell Packages]
* [http://www.cse.unsw.edu.au/~dons/papers/CPJS08.html Haskell: Batteries Included], position paper by Don, Duncan and Isaac.
== Documentation ==
== Documentation ==

Revision as of 20:37, 4 May 2009


The Haskell Platform (HP) is the name of the blessed, core library suite for Haskell. By taking the best libraries from the more than 1200 libraries of Hackage, it provides a comprehensive, stable and mature base for Haskell projects to work from.

See the Platform Issue Tracker for further information.


The platform is specified via a Cabal file:

The initial release targets:

  • ghc-6.10.2
  • Classic Extra Libs
  • haddock, happy and alex
  • cabal-install and its dependencies.


Distros that support the Haskell Platform

System Status
Arch To be constructed with cabal2arch
Gentoo Available in the gentoo haskell overlay, large parts in portage
Nix(OS) Metapackage available for testing in Nixpkgs
Generic Unix Installer
Windows Installer
OSX Installer

Volunteers needed!

We are calling for volunteers for an action group. We need volunteers to take charge of various platforms and to manage the overall release. We would like to release a beta at the upcoming Haskell Hackathon in Utrecht (April 17-19). However this will only happen if people volunteer to help build distributions for different platforms.

In particular we need:

  • Release manager / coordinator
  • Website with downloads and release notes
  • Someone in charge of each platform:
    • Windows installer
    • OSX installer
    • Generic Unix source tarball
    • Distribution packages: debian, fedora, gentoo, arch, BSD* etc

The person in charge of each platform is responsible for building a appropriate native packages / installer and coordinating the effort to test that the stuff installs and works ok.

If no one volunteers, we simply won't have an Haskell Platform release for that platform.

Please join the mailing list and volunteer!

Hackathon Update

We finalised the list of packages that will be in the first release. See: http://trac.haskell.org/haskell-platform/wiki/Library/VersionMatrix

We managed to get a beta version of the generic tarball for unix systems. Get that here and try it out: http://haskell.org/~duncan/haskell-platform-2009.0.0.tar.gz

Chris and Eelco made a very nice design for the front page of a "Get Haskell" download site for the platform.

Gregory reported progress on the OSX front. Turns out there will need to be more work to do new OSX Leopard-style installers.



Quality Control

Inclusion or exclusion in the platform will be driven by metrics, objective measurements we can extract from code. Determining appropriate metrics is a milestone.

  • cabal-installable libraries with haddocks.
  • packages should follow the Package versioning policy
  • The set of HP packages + core libs must be closed. In other words, all haskell dependencies must be from within the HP packages or core libs. Dependencies on C libs can be external.
  • All packages in a particular HP version must have a consistent install plan.

That means only one version of each package and all dependencies on packages must be satisfied by the version in the HP package set.

There is code in cabal-install to check the last two requirements.

Other possible ideas for quality standards we might want to require:

  • Uses base library types, to force API standardisation
  • exposed module names must follow the hierarchical module name convention, meaning they must be in an appropriate place in the module namespace. In particular, no clash of module names should occur within the HP.

Other heuristics

Packages set for inclusion should:

  • Have a maintainer
  • Have a bug tracker
  • Use the correct versioning
  • Build with cabal
  • Work on all arches.

Further goals:

  • -Wall clean
  • 100% coverage
  • Have real world use.
  • Answer a notable set of build dependencies.
  • Have a declared correctness test suite.
  • Have a declared performance test suite.
  • BSD licensed

Distribution format

  • Source distribution
  • .tar.gz bundle compatible with extra-libs
  • Windows Installed
  • Native distro packages

The HP will be the first meta-package on hackage, that depends on the platform library set. With this,

   cabal install haskell-platform

will be possible.

Version policy


  • odd major numbers indicate unstable branches
  • minor numbers indicate bug fixes only, no API changes.


  • 2008.0.0 -- first biannual major stable release
  • 2008.0.1 -- minor release, bug fix only
  • 2008.1 -- unstable branch leading to next major release
  • 2008.2.0 -- second annual major release, API changes
  • 2008.2.1 -- bug fixes
  • 2008.3 -- unstable branch of 2008
  • 2009.0.0 -- first release in 2009.

Additionally, if a library is accepted into the platform, it is suggested its version number be lifted to 1.0, if not already at 1.0.


The initial release is expected to include only BSD3 licensed software.


The platform includes programs, such as haddock or cabal-install. These aren't nicely tracked from the cabal meta package yet.

Build system

Two ways to build the bundle:

  • generate a sh script from the .cabal file

Or, build cabal-install, have the components of the platform as a mini, local hackage archive, and then ask cabal install to satisfy and install the dependencies from the platform meta-cabal file.

Related projects


Haskell Platform core team:

  • Duncan Coutts (Well Typed)
  • Don Stewart (Galois)