Wikipedia is a free encyclopedia that can be edited by any vistor to its site. What started as an English language project has turned into an extensive resource in hundreds of languages, written from a "neutral point of view." The site claims that it is built on the idea that more collaboration will lead to better articles, but it has faced controversy with critics who decry the lack of a review process. In any case, it has a wealth of knowledge that you definitely do not want to miss. Learn how to edit in the Wikipedia: Introduction section or find out how to cite Wikipedia as a reference in FAQs.