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.
SSD (Sawfish Session Dialog) is a small and flexible wrapper for session commands. It is intended to be used with Sawfish, but does not require it. It can be configured to use any command for logout, reboot, shutdown, suspend, hibernate, and lock actions. Preset command definitions are available for: KDE4, GNOME2, XFCE4, MATE, and Razor-Qt. It is part of Sawfish-Extras (currently there's only SSD, but more is planned).