Xfce Embed Plugin enables the embedding of arbitrary application windows into the Xfce panel. The window is resized into the panel space available, and the associated program can be automatically launched if it is not open. Example uses include embedding an instant messaging buddy list, a mail client's new mail ticker, a simple media application, or a fancy clock or timer. Combining with Xfce's ability to auto-hide panels can make this very convenient.
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.