All objects in the applet have the same mass m. The three rolling objects, hoop, disk, and sphere, all have the same radius r.
There is no dissipative friction between the objects and the incline. The applet does allow friction to affect the motion of the three round objects, but this friction does not reduce the mechanical energy of the objects.
The applet shows the energies in 1-J chunks. In reality, as the objects move down the inclines, the various energies change continuously.