Learning coding online

A lot of online courses for coding skills are available nowadays, both free and non-free. I will collect this kind of websites (ever spent some hours on each one) here.

1. Coursera: Free

https://www.coursera.org/

A nice MOOC website for various courses, some coding lessons also.

2. codecademy: Free

http://www.codecademy.com

A coding course website on web programming. I have completed some lessons on it. All courses are interactive and contain pieces of code to each task.

3. Treehouse: Non-free

http://teamtreehouse.com

This is the first one I paid some $$ to learn, though still on a free-trial plan until next month. It has some course other than coding, both design and business, such as how to be a freelancer.