In the last few days I’ve been checking out some haskell GUI frameworks. This is what I found so far.

Gtk2Hs

As the name says, Gtk2Hs is a library which bases on the Gtk+ project. It supports native look’n'feel and is supported on Linux, MacOS and Windows. You can even use the glade interface builder on Linux for creating your Haskell guis.

The user interface code is implemented in one big Monad (how else?) and a hello world application looks like

import Graphics.UI.Gtk
 
main :: IO ()
main = do
  initGUI
  window <- windowNew
  button <- buttonNew
  set window [ containerChild := button ]
  set button [ buttonLabel := "Hello World" ]
 
  onClicked button (putStrLn "Hello World")
  onDestroy window mainQuit
  widgetShowAll window
  mainGUI

wxHaskell

wxHaskell is a Haskell like wrapper built on top of the C++ wxWidgets framework. It runs on all major platforms as well and supports native look’n'feel. The MacOS port is available as a darcs repository.

The example.

module Main where
import Graphics.UI.WX
 
main :: IO ()
main = do
  f <- frame    [text := "Hello World"]
  quit <- button f [text := "Quit", on command := close f]
  set f [layout := widget quit]

HOC

On http://hoc.sourceforge.net/ there are Objective-C bindings so it is possible to access MacOS’ Cocoa library from Haskell and build Cocoa objects from Haskell.

[Update]

Eric pointed out some mistakes.