Haskell is a general-purpose, statically typed, purely functional programming language with type inference and lazy evaluation. Developed to be suitable for teaching, research and industrial application, Haskell has pioneered a number of advanced programming language features such as type classes, which enable type-safe operator overloading. Haskell’s main implementation is the Glasgow Haskell Compiler (GHC). It is named after logician Haskell Curry.
Haskell’s semantics are historically based on those of the Miranda programming language, which served to focus the efforts of the initial Haskell working group. The last formal specification of the language was made in July 2010, while the development of GHC’s implementation has continued to extend Haskell via language extensions. The next formal specification is planned for 2020.