AoPS was started by Richard Rusczyk, who participated in national math competitions in high school and went to Princeton. AoPS wrote a set of math texts for Algebra to Calculus, has online, interactive classes for high school math and computer programming, they also have a series of elementary math books called Beast Academy in cartoon format.
The online classes meet once a week for 1.5 hours. The students have homework which consists of about 10 problems per week and reading the textbook. The courses run for 13 weeks and cost around $340. The series of courses include the standard pre-algebra to calculus series, number theory, probability, group theory, math competitions and computer science. New classes sections start every month and run year round.
GiftedandTalented.com (formerley Stanford EPGY) is a computer based math and language arts for K-8 and high school. The online math class is starts in 1st grade and goes through Algebra 1. The online class is self-paced and adaptive. The format of the class is a short three minute video on a new topic, then a series of problems for the student. If the student answers the problems correctly, then move on to the next topic and watch a new video. If the student misses a problem, they are given more problems to work or hints to help them solve the problem. They can also go back and re-watch the video. The course has a well thought out curriculum that follows curriculum standards. The software tracks the student’s progress in detail. The pace of the course can be adjusted by the parent.