homework help and self-study guides for middle and high school students is NutshellMath, an online service that provides interactive math explanations and multimedia demonstrations of math concepts. NutshellMath is predominantly comprised of 50,000 tailor-made videos that are aligned with commonly-used math textbooks in the U.S. These videos were created by approximately 400 teachers using the Academy123 content development platform. Academy123 pioneered the ""listen and view"" instructional format that was later popularized by Khan Academy.

Academy123 was founded by Maury Friedman and Yarone Goren in January 2004 and is based in Westlake Village, California. The company was acquired by Discovery Education, a division of Discovery Communications, on July 5, 2006.