Haskell is a standardized purely functional programming language with non-strict semantics, named after the logician Haskell Curry. It is one of the more popular functional languages, and the lazy functional language on which the most research is being performed.

Although Haskell has a comparatively small user community, its strengths have been well applied to a few projects. Audrey Tang's Pugs is an implementation for the forthcoming Perl 6 language with an interpreter and compilers that proved useful already after just a few months of its writing. Darcs is a revision control system, with several innovative features. Linspire GNU/Linux chose Haskell for system tools development.