Coursera - Build skills with courses, certificates, and degrees online from world-class universities and companies
CodeShare.io - Realtime code sharing for developers
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.
Code.gov - Share & reuse open source code from the Federal Government
edX - Best Courses. Top Institutions. Learn anytime, anywhere.
CodeMyUI - Handpicked code snippets you can use in your web projects