Haskell is a statically typed, purely functional programming language. It takes its name from the mathematician and logician Haskell Curry. The language is designed to be expressive, concise, and safe, with a focus on immutability and referential transparency.
The Haskell language has evolved significantly since its birth in 1987. This tutorial deals with Haskell 98. Older versions of the language are now obsolete; Haskell users are encouraged to use Haskell 98. There are also many extensions to Haskell 98 that have been widely implemented.
