In the X Window System, the X Nonrectangular Window Shape Extension allows windows to be given arbitrary, non-rectangular shapes.
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. Most X Window systems have one or the other (or both) in their standard installations. In addition, some window managers use the shape extension to draw non-rectangular icons.
... alterations Bridgwater and West Somerset 77,780 82,936 Somerset Extension of existing seat Brigg and Goole 62,246 66,734 Humberside Little change Brighton ... Central 78,941 80,912 West Yorkshire (Leeds) Modifications in size and shape Leeds East 67,571 64,742 West Yorkshire (Leeds) Modifications in size and shape Leeds North. 68,244 71,706 London (Harrow and Hillingdon) Extension of existing constituency Runnymede and Weybridge 73,357 73,680 Surrey Unchanged Rushcliffe 70,484 73,430 Nottinghamshire Minor ...