Haskell is one of the leading languages for teaching functional programming, enabling students to write simpler and cleaner code, and to learn how to structure and reason about programs. Haskell is unique in two ways. First, it is a pure functional programming language. If you have a function and you call it twice in two different places with the same arguments then it will return exactly the same value both times. Second, Haskell provides a very modern type system which incorporates features like typeclasses and generalized algebraic data types. (we hope terms like these will roll smoothly off your tongue by the time you're done.)
Prelude> "Hello, World!" "Hello, World!"