GTK System Driver (since 3.0)
This driver was designed for the GTK+ version 2. It can be compiled in Windows or UNIX.
Tips
Although the GTK driver can be compiled and used in Windows, it is not recomended since it is slower and much more memory consuming than the IUP native Windows driver.
Although GTK has layout elements they are not used. IUP fill, vbox, hbox and zbox containers are implemented independent from the native system.