xstroke is a full-screen gesture recognition
program written for the X Window System. It
captures gestures that are performed with a
pointer device, (such as a mouse, a stylus, or a
pen/tablet), recognizes the gestures and performs
actions based on the gestures. xstroke has been
developed on Linux systems, (i386 and StrongARM),
but should be quite portable to any UNIX-like
system with X.