Podia - Podia is your all-in-one digital storefront. The easiest way to sell online courses, memberships and downloads, no technical skills required. Try it free!

Khan Academy - Khan Academy offers online tools to help students learn about a variety of important school subjects. Tools include videos, practice exercises, and materials for instructors. Read more about Khan Academy.

udemy-dl - Download courses from Udemy for personal offline use

edX - Best Courses. Top Institutions. Learn anytime, anywhere.

Codecademy's Learn C++ - Learn one of the most powerful languages in the world! 👾

Coursera - Build skills with courses, certificates, and degrees online from world-class universities and companies