Complex sentence: Touch-screens often use "inertial scrollling" which will continue the scrolling motion in a decaying fashion after release of the touch, simulating the appearance of an object with inertia; an early implementation was in the "Star7" PDA of Sun Microsystems ca.
Split into simpler sentences: Touch-screens often use "inertial scrolling", in which the scrolling motion of an object continues in a decaying fashion after release of the touch, simulating the appearance of an object with inertia. An early implementation of such behavior was in the "Star7" PDA of Sun Microsystems ca.