GTK+
<graphics, interface, library, open source> ("The GIMP ToolKit", or (bogusly) "
Gnu ToolKit" or "Generic ToolKit") A multi-platform toolkit for creating graphical user interfaces.
Offering a complete set of widgets, GTK+ is suitable for projects ranging from small one-off projects to complete application suites.
GTK+ consists of the three parts; GLib, providing basic data structures, event handling, threads, etc., Pango, for layout and
rendering of text, and
ATK, providing interfaces for accessibility.
GTK+ Home (http://www.gtk.org/).