College-level mathematics classes for advanced high school students who have exhausted the curriculum available at their own schools. Courses run from introductory offerings such as Mathematical Thinking and Transition to Proofs through advanced topics including generating functions, and culminate in an independent research and paper-writing class. Teaching is hybrid, combining in-person sessions in Palo Alto with online participation, and summer sessions are fully online so students anywhere in the world can take part. The programme deliberately emphasises mathematical depth and research rather than competition training.