Hi! I am writing a calculus-based Introduction to Electricity and Magnetism. It is an HTML-based book with animations, interactive demos, quizzes, and so forth. The first draft is almost complete (I still have to write chapters on integration, induction, and wave optics), but I wanted to share it with a wider audience and look for feedback. If you're interested in following along in its development, please let me know. I've set up a Google Plus page for the book and for a related online class which I'll mention in another post. Thanks!