GTK+ will support rendering directly to the framebuffer instead of using the X Window System.

This is good for embedded systems such as PDAs and other systems with very limited resources, because they are able to run without the overhead of an X server while still taking advantage of the power of GTK+ and the large base of existing programs. This whitepaper describes how GTK+ for the Linux framebuffer works, its advantages and limitations, how it fits into the environment, and how to obtain the software.

GtkFB is runs without any external windowing System. Instead, the framebuffer port runs stright on the linux framebuffer device.

GtkFB is not really ment to the run on the desktop.its ment for PDAs.

If want to know more about GtkFB click this link

http://www.linuxdevices.com/articles/AT9024868021.html