wxHaskell

wxHaskell is a portable and native graphical user interface (GUI) library for the programming language Haskell, built on wxWidgets.

It is often used by those wanting to develop a graphical user interface (GUI) with a functional programming language.

[1] wxHaskell is a middle-level GUI library.

[2] Several experimental high-level GUI library approaches are implemented on wxHaskell: In contrast, the high-level GUI libraries FG and Grapefruit are implemented on the middle-level Gtk2Hs, which is based on GTK2.

All of these high-level libraries are experimental, using advanced mathematics concepts in their approach (see Arrow (computer science)).