SonarQube - SonarQube, a core component of the Sonar solution, is an open source, self-managed tool that systematically helps developers and organizations deliver Clean Code.
Coverity Scan - Find and fix defects in your Java, C/C++ or C# open source project for free
edX - Best Courses. Top Institutions. Learn anytime, anywhere.
Geocities Site Builder - Share your abomination with the world
Embold.io - Peer Code Review
Treehouse - Treehouse is an award-winning online platform that teaches people how to code.