Mathipedia.com is a site dedicated to making mathematics accessible to everyone in ways that are simple to understand and presented in different forms for different learning styles.
Mathipedia has a goal of providing resources that can be used by students, parents, and teachers free of charge without strict copyright restrictions. Here is what you will find on this site:
Music Theory is an excellent site by Ricci Adams designed to teach different aspects of music such as: exercises, lessons, and tools. This really is a great site for music teachers as a user can use custom made tools for their lessons.
With VocabSushi, flash cards are a thing of the past. The best way to build your vocabulary is not rote memorization. It's seeing how words are used in everyday language. VocabSushi helps you prepare for the ISEE, SAT, ACT, GRE or other standardized test by teaching you vocab words with real-world, contextual examples found in the daily news.