Gtk (GTK+) is a Graphics Toolkit written in C, primarily developed for use with the X Window System. GTK+ is licensed under the GNU LGPL license and has bindings for many languages including Ada95, C++, Common Lisp (see GTK bindings), Dylan, Eiffel, Guile, Haskell, JavaScript, Objective C, Objective Caml, Objective Label, Pascal, Perl, Pike, Python, and TOM. It's a major component of the GNOME project.

More information can be found at

Common Lisp GTK bindings, etc. on Cliki:

  • cl-gtk2 - CL-GTK2 is a Common Lisp GUI library that provides access to the Gtk+ cross-platform GUI library in idiomatic Lisp style
  • GNOME - GNOME is the GNU Object Model Environment, intended to provide a user-friendly "desktop environment" for UNIX operating systems
  • GTK binding - This page lists Common Lisp bindings for the GTK GUI toolkit
  • gtk-cffi - GTK-CFFI is a Common Lisp GUI library, that provides concise and idiomatic syntax to use GTK+ library (for now GTK+ 3.0)

GTK can also be used with Lisp through GTK-server.