The Mathematical Association of America's online Digital Classroom site offers no faint praise for this interactive set of tools, noting that "it is exciting, fast, and fully object-oriented". This is all true, and educators in both mathematics and the sciences can use this application to create their own customized, web-based learning aids. Developed by Doug Ensley of Shippensburg University and Barbara Kaskosz of the University of Rhode Island, these tutorials come complete with an overview, some basic information on its constructs and interactions, and a set of guidelines to follow to create meaningful and compelling learning aids for students. Overall, it's a very fine resource, and one that interested parties will be able to use in a variety of settings.