The GUIShell project is a collection of utilities facilitating the use of the GTK+ toolkit in shell scripts through the gtkshell utility. The ACE configuration environment provides sample scripts utilizing gtkshell for desktop utilities. rootcat provides the ability to display messages to the root window using Xft, allowing one to write status display scripts.
The primary aim of the Gtk+2 panel project is to provide a panel that reuses whatever is available (if it is not overkill) in the obvious way, such as subclassing GtkWidget instead of implementing applets, or by using a GtkBuilder file instead of defining a new format to customize the panel. This approach gives some additional advantages for free: you can use common tools in uncommon ways. Above all, you can use Glade to design your own panel. All the dependencies apart from GTK+ are (and hopefully will be) optional.