Good Gear Guide
In Pictures: The story of the Picasso and a 1.5 to...
According to a Wikipedia entry, a Cartesian coordinate robot (also called linear robot) is an industrial robot whose three principal axes of control are linear (i.e. they move in a straight line rather than rotate) and are at right angles to each other.
In Pictures: The story of the Picasso and a 1.5 ton robot