Macromedia Flash, a program commonly used to create compact Web animations, has a tweening function. If we wanted to have a robot hover from left to right we would begin by generating one instance of that robot and placing it on the left of a keyframe. Then we would make a copy of the robot and place it on the right side of another keyframe. Finally, we would have Flash tween from the robot on the left to the one on the right, from one keyframe to the other. The result would be an animation consisting of two keyframes and numerous tweened frames in between them.