PhET provides free interactive simulations for physics, chemistry, biology and mathematics that visualize scientific concepts.
A collection of informal explanations and demonstrations of classical physics phenomena and electrical engineering.
Online physics and chemistry instruction with interactive tools for students.
Site explaining vector calculus and mathematical concepts with visual intuition.
Interactive visual explanations of physics concepts through play-based learning.
Fizalis is a Russian physics education website offering theory, worked examples, and problems across classical and modern physics.
Russian educational encyclopedia covering many subjects including physics.