When enabled, the Panning option on the Xconfig Screen page lets you pan across the server window to view parts of X application windows that are off screen when you are running the native window manager only.
The method of panning depends upon whether or not you select the Full Screen setting in the Window Mode area of the Screen page. If you select Full Screen, you can pan up or down to display or hide the window title bar and left or right to display or hide part of the native desktop.
When focus is on the X application window, you can move the mouse pointer to the edge of the screen to view off-screen information.