Codeasy is probably the newest one from the whole list. It is quite interesting educational course because it drives a new concept to computer science studying. You start learning there by reading an adventure story about fighting machines in the future. On your way, you’ll meet challenges that require real coding to solve. The final goal is to save the world from machine invasion. And as a very important side effect – become a software developer.
EdX is another leading online-learning platform that is open source instead of for-profit. It was founded by Harvard University and MIT in 2012, so you know that you’ll learn about cutting-edge technologies and theories. Today, edX includes 53 schools. You probably can’t go wrong with the free Introduction to Computer Science from Harvard University.