A set of modules for creating compilers in Haskell. [Open Source, GPL]

Helps you build web applications in Haskell.

A high level library for building GUIs in Haskell. It provides good support for developing complex dynamic systems, and is built on top of Tcl/Tk. [Open Source, BSD-like]

Graphical User Interface toolkit for Haskell and X Window system. [Free non-commercial use]

Bindings for GTK+ for Haskell.

Multi-threaded, concurrent user interface framework for Haskell, X Window.

Haskell Gnome and ORBit effort and bindings

An ODBC interface to Haskell implemented using Green Card.

A portable graphics library for both X11 and Win32. [Open Source, BSD-like]

An OpenGL/GLUT binding for Haskell. [Open Source, LGPL]

A bridge to the Java virtual machine via JNI for Haskell. [Open Source, LGPL]

An interface to the database MySQL for the programming language Haskell. [Open Source, LGPL]

Native Haskell implementation of polymorphic regular expressions. The regexps contains most of the features found in Perl.

Useful for building graphical user interfaces through the Tcl/Tk. [Open Source, BSD-like]