Terraform requires libglib 1.2.x, libgtk 1.2.x and libgtkmm (gtk--, the C++ Gtk wrapper) 1.0.x and (optionally) imlib 1.8.x. Terraform does not (yet) use the gnome libraries.
I intend to stay with the stable version of libgtk and libgtkmm for the time being, so starting with version 0.2.8 (theoretically) any revision of glib/gtk 1.2 and Gtk-- 1.0 should work (see the FAQ or the terraform homepage for the latest details on this). Configure will check for an appropriate version of Gtk and Gtk--.