The wave simulator, created by Paul Falstad, can be used to create a wide range of demos with reflectors, lenses, cavities, and point sources. Common examples such as multiple source and multiple slit interference, Doppler effect, and beats are available, along with more advanced topics such as waves in confined geometries, wave scattering, and temperature gradients. Very little documentation on how to use the simulator is provided but the controls are somewhat self-explanatory.