GTK is a popular toolkit for creating programs with a graphical user interface that works with the X Window System or, more recently, Wayland. Such toolkits provide programmers with easy ways to create windows, menus, pop-up dialogs, and other common ways to interact with graphical programs. Licensed under the LGPL license (GNU Lesser General Public License), GTK is free (and open-source) software, and is part of the GNU Project. This means you are granted certain freedoms such as being able to inspect the code, change it, and distribute your modifications.
Desktop environments and window managers that use GTK
GNOME environment uses GTK as a base, which means that programs written for GNOME use GTK as their toolkit.
MATE, a fork of the GNOME 2 desktop
Xfce also uses it as their base, though its applications typically do not depend on as many programs. (This is the difference between something being branded as a "GNOME program" and as a "GTK program".)
- The GPE Palmtop Environment and Maemo, Nokia's internet tablet framework, also use GTK as a base.
- Fluxbox uses GTK.
GTK official website is https://www.gtk.org