Applications and libraries
The number of Haskell packages is growing exponentially. The section 'Haskell library collections' gives an ordering of all these packages by relative importance. In the section 'Haskell applications and libraries' an ordering by category is given. Finally some guidelines for developers of new packages are presented.
Haskell library collections
The most import Haskell library is called the Prelude. It is implicitly imported by default, and includes the most commonly used functions. Make sure you know what they do and how to use them.
The Haskell 2010 Libraries
The Haskell 2010 Language and library specification defines a set of libraries with basic functionality which all Haskell implementations should support, including the Prelude. Changes to these libraries are handled by the Haskell' process.
The GHC standard libraries
GHC comes with an expanded version of the Haskell 2010 libraries. Together these are called the GHC standard libraries. Changes to these libraries are handled by the package maintainer if one exists, or the Library submissions process if not. Hoogle - the Haskell API Search Engine - indexes the GHC standard libraries.
Haskell Platform libraries
On top of the GHC standard libraries, the Haskell Platform comes preinstalled with some additional packages that together form the Haskell Platform libraries. The extra libraries have been thoroughly tested and found industry worthy to be included as extra batteries.
The Hackage database aims to be a comprehensive collection of released Haskell packages, similar to Perl's CPAN or Python's PyPI.
Haskell applications and libraries
Applications, libraries and tools for Haskell or written in Haskell have been classified below, but you should check Hackage for the latest list.
- Audio, music and sound
- Concurrency and parallelism
- Compilers and interpreters
- Compiler construction, lexing, parsing, pretty printing
- Cryptography and hashing
- Data Structures and IO Libraries
- Database interfaces
- Editors written in Haskell and editors for Haskell.
- Extended Haskell
- Genetic programming
- Graphical User Interface (GUI) Libraries
- Hardware verification
- Linguistics and natural language processing
- Mathematics and physics
- Operating systems and systems programming (also emulators)
- Program development
- Theorem provers
- Tools for interfacing with other languages
- Web, HTML, XML
Other places to look include:
- The Library hierarchy page on this wiki.
- The Haskell community reports.
- The mailing list for discussion of issues related to libraries.
Guidelines for developers
- How to write a new Haskell library
- How to propose changes to the standard libraries
- Creating a .deb from a Haskell Cabal package
- Creating a Haskell library by example
- Guide to making standard library submissions
- If you notice the library documentation is lacking, or could be improved, please report it here
- Google Code Search can help identify common idioms, improving your API.
- Future projects, more projects people would like.
- Project activity for some of the larger Haskell projects is graphed here.
- Cabal, The Common Architecture for Building Applications and Libraries, is a framework for packaging, building, and installing any tool developed in the Haskell language.
- Hack-Nix, a set of tools based on the Nix package manager to manage multiple setups to build a project
Proposals for the module name space layout that can be used to guide the construction of new libraries.
Libraries for other languages
If you are thinking about designing a new library for Haskell, you ought to look what has been done in other languages. Here are standard library definitions for