GTK
From AMule Project FAQ
GTK (Gimp Toolkit) is a multi-platform toolkit for creating graphical user interfaces, offering a complete set of widgets.
It is free software (licenced under the LGPL license) and was initially developed for the Gimp application.
aMule is linked against GTK (through wxWidgets) in many Linux and BSD systems.
GTK's official web site: http://www.gtk.org
NOTE: aMule is a separate project and is not realated to GTK in any way.
