Khan Academy

Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere.


Ideas worth spreading.  TED Talks are influential videos from expert speakers on education, business, science, tech and creativity, with subtitles in 100+ languages. Ideas free to stream and download.

A complete guide of every Mac, iPod, iPhone, iPad and Mac clone with technical and pricing info. Specs on every Mac, answer Mac questions, compare Macs...

Stack Exchange

Stack Exchange is a network of 162 communities that are created and run by experts and enthusiasts like you who are passionate about a specific topic. We build libraries of high-quality questions and answers, focused on each community's area of expertise.