The &xbutton; widget simply displays a button with the &xwp; "X" eComStation logo on it. If you press that button, a menu will open which gives you access to functions like shutdown, suspend, logoff, and "Restart Desktop".

Besides, the &xbutton; menu will display the contents of the Desktop, just like the regular &xwp; folder content menus do.

You can change the menu items and the bitmap that is displayed by right-clicking on the &xbutton; and selecting "Properties".