Khanpedia is a Chrome extension that integrates Khan Academy content (videos and exercises) into Wikipedia. With the extension installed, clicking certain links on Wikipedia (the green ones!) will present the user with the option of viewing that topic on Khan Academy or on Wikipedia. 

Khanpedia is an *unofficial* intern hackathon project from Khan Academy's first inaugural Healthy Hackathon. It's open source, too: https://github.com/dylanvee/Khanpedia