Considering the fact that Discovery Communications bought HowStuffWorks for $250 million, their emphasis on quality should come as no surprise. They use various forms of media to explain a wide variety of complex subjects.
FreeRice is a way of building your vocabulary while doing a good deed. The website is sponsored by the World Food Programme which aims to help end world hunger. On FreeRice, you are presented with vocabulary questions. For every vocabulary question you get right, the World Food Programme will donate 10 grains of rice to help fight world hunger. Pretty cool, right? FreeRice also has options for answering questions about geography, foreign languages, paintings, and more.