Physics & Astronomy
Astropedia - An astronomy learning tool, created by University of Arizona Astronomy professor Chris Impey, intended either as a supplement for classroom instruction or for informal learners wanting to know more about the subject.
PhET - started by Nobel Laureate Carl Weiman as a resource for physics instruction; it contains “interactive simulations for science and math
Physics LibreTexts - a multi-institutional collaborative venture to develop the next generation of open-access texts to improve postsecondary education at all levels of higher learning. The LibreTexts approach is highly collaborative where an Open Access textbook environment is under constant revision by students, faculty, and outside experts to supplant conventional paper-based books. The LibreTexts project is currently directed by UC Davis Professor and project Founder Delmar Larsen.