Encyclopedia Britannica was founded 240 years ago. It contains approximately 150,000 articles in English. Wikipedia was founded in 2001. It contains 1.7 million articles in English, approximately 7.2 million in 251 languages. The range, scope and detail of articles on Wikipedia is so much greater because it harnesses the power of the Internet to access a much larger pool of knowledge and expertise than any other encyclopedia. How was such a remarkable feat possible?