Helium is a compiler and a dialect of the functional programming language Haskell. It has been designed to make learning Haskell easier by giving clearer error messages. It is being developed at Utrecht University, Netherlands, primarily by Arjan van IJzendoorn, Daan Leijen, Bastiaan Heeren and Rijk-Jan van Haaften. Certain language features of Haskell have not been included to create more specific error messages. For this reason, it (currently) lacks type classes, rendering it incompatible with many Haskell programs.