GTK - The Gimp Toolkit
GTK is 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 is free software and part of the GNU Project. However, the licensing terms for GTK , the GNU LGPL, allow it to be used by all developers, including those developing proprietary software, without any license fees or royalties.
GTK was initially developed for and used by the GIMP, the GNU Image Manipulation Program. Therefore, it is named "The GIMP Toolkit", so that the origins of the project are remembered. Today GTK is used by a large number of applications, and is the toolkit used by the GNU project's GNOME desktop.
GTK has been designed from the ground up to support a range of languages, not only C/C . Using GTK from languages such as Perl and Python (especially in combination with the Glade GUI builder) provides an effective method of rapid application development.