Haskell is standardized, general-purpose compiled purely functional programming language. Haskell is written in several languages but it's basically a mixture of C and Assembly. This language was created, by the whole team, that included:
Simon Peyton Jones
Haskell has a lot of features, the most known, are here:
cache in functions
Haskell specification is published and open for everyone. Glasgow Haskell Compiler (GHC) is its main implementation, which is both, native-code compiler and interpreter, that runs on most of the platforms.
File extensions for Haskell code are .hs and .lhs