Another is PingPongPlus, a digitally enhanced version of the classic table tennis. It is played with ordinary, un-tethered paddles and balls, and features a "reactive table" that incorporates sensing, sound, and projection technologies. Images of water and a school of fish are projected onto the surface of the ping pong table. Each time the ball hits the table, the computer sense its position, causing the images of ripples to spread out from the ball and the fish to scatter. It enhances the experience of playing ping pong.