The fundamental principles by which Wikipedia operates are the Five pillars. The Wikipedia community has developed many policies and guidelines to improve the encyclopedia; however, it is not a formal requirement to be familiar with them before contributing. Since its creation in 2001, Wikipedia has grown rapidly into one of the largest reference websites, attracting nearly 78 million visitors monthly as of January 2010. There are more than 91,000 active contributors working on more than 16,000,000 articles in more than 270 languages. As of today, there are 3,467,236 articles in English. Every day, hundreds of thousands of visitors from around the world collectively make tens of thousands of edits and create thousands of new articles to augment the knowledge held by the Wikipedia encyclopedia. (See also: Wikipedia:Statistics.)