This Demonstration shows snapshots of a disk rolling on a plane. For the calculation, it is assumed that the disk has infinitesimal thickness, rolls without friction, and does not slide or slip. Thickness is allowed so as to give a more interesting image. A rolling disk is one of the simplest examples of a nonholonomic system. It is completely integrable, and as a result, the sequence of snapshots form nonchaotic sequences exhibiting a certain symmetry.