Haskell (source: ghc.io)

Haskell is a pure functional programming language that is conceptually very expressive. Haskell code is sometimes called “runnable specification”. It is a mature language with lots of excellent documentation, libraries and tools support, making it an enterprise-grade solution.

Haskell’s strong type system is considered the best one used in enterprise. It has a great expressive power, while not limiting polymorphism.

There are several compilers into the native code (GHC being the most famous) and also several compilers into JavaScript, which makes Haskell also a client-side web development language, solving the “JavaScript problem“.

A good number of thematically-sorted resources are available on our wiki page.