This math system covers grades 1 through 12 and is focused on helping students develop good "mental math" habits. It looks like the sort of program that will work very well for some students, but not others. It is reasonably priced, and there are some sample pages available for you to try.
Online, interactive program for learning music reading and theory.
This non-profit organization offers over 100 free self-paced, online, college level courses.
This online math program is designed to help students with math problems (including dyscalculia.)
This hands-on grammar curriculum includes CD ROMs, teacher manuals, and games for learning gramma
Online, super-hero themed science games for elementary and middle school levels.
This program includes videos, worksheets and quizzes for history learning in jr.