Education
MIT OpenCourseWare publishes the full materials from MIT's 6.006 Introduction to Algorithms: lecture videos, lecture notes, problem sets, and exams — all free. The course covers sorting, hashing, dynamic programming, graph algorithms, shortest paths, and complexity theory. It is mathematically rigorous and the closest thing to an actual MIT education you can get for free. A must-take for developers who want to go deep on computer science fundamentals and interview prep.