Two well-known applets that use the shape extension are oclock, which is a simple round analog clock, and xeyes, which shows two googly eyes that follow the cursor on the screen as if they were watching it.

In addition, some window managers use the shape extension to draw non-rectangular icons.

Applications can only create rectangular windows, but can then change their shape to be an arbitrary part of the original rectangle.

Both the clipping and bounding are associated, in the shape extension, two areas: a default rectangular region and a possibly non-rectangular client region, defined and changed by the client as specified above.

The effective region, which is the actual shape of the window, is the intersection of these two areas.