This set of tutorials provides a carefully crafted exploration of waves, a topic of importance to a great many fields of physics. The completeness of the topics covered is particularly noteworthy.
The java simulations are generally simple and do an excellent job of linking the mathematical description of waves with visual representations. The user can manipulate individual parameters in the models to explore the physical properties of the systems being studied. The tutorials cover topics which students often find difficult, such as phase and group velocity, longitudinal waves, interference, and dispersion. Connections are made between the physical motion of matter or fields in these waves and the graphical representations used to describe this motion.
The combination of visualization and mathematics, where students can explore the physics by manipulating both graphical and mathematical models of the waves, is important and noteworthy.
Some of the tutorials discuss the simplifications made in the models being used. This is important to help students understand the applicability of the models. More of these discussions would be useful.