Quora, founded in June 2009, first launched in private beta in January 2010.
Quora is a continually improving collection of questions and answers created, edited, and organized by everyone who uses it. The most important thing is to have each question page become the best possible resource for someone who wants to know about the question.
One way you can think of it is as a cache for the research that people do looking things up on the web and asking other people. Eventually, when you see a link to a question page on Quora, your feeling should be: “Oh, great! That’s going to have all the information I want about that.” It’s also a place where new stuff–that no one has written about yet–can get pulled onto the web.