The linux-fb port of GTK+, also known as GtkFB is an implementation of GDK (and therefore GTK+) that runs on the Linux framebuffer. It runs in a single process that doesn't need X. It should run most GTK+ programs without any changes to the source.
First build and install GLib, ATK and Pango as usual, in that order. Then configure GTK+ by running configure (or autogen.sh if running from CVS) with --with-gdktarget=linux-fb.