Haskell is a general purpose, purely functional programming language. Haskell compilers are freely available for almost any computer. A Short Introduction to Haskell Haskell in Education Applications Written in Haskell Definition of the Language and the Standard Libraries Communities and their Projects The Future of Haskell Haskell Compilers and Interpreters Libraries and Tools for Haskell Books ...

The Glasgow Haskell Compiler is a robust, fully-featured, optimising compiler for Haskell 98, GHC compiles Haskell to either native code or C. It implements numerous experimental language extensions to Haskell 98; for example: concurrency, a foreign language interface, multi-parameter type classes, scoped type variables, existential and universal quantification, unboxed types, exceptions, weak pointers, and so on. GHC comes with a generational garbage collector, and a space and time profiler.

Functional languages like Haskell are ideal for implementing compilers. Complemented with a lexer and parser generator, they provide much of the functionality and ease-of-use associated with specialized compiler tools (aka compiler compilers) while being more flexible, better supported, and guaranteeing better long time availability.