Wikipedia.org is a multilingual, web-based, free content encyclopedia project. The name Wikipedia is a portmanteau of the words wiki (a type of collaborative website) and encyclopedia. Wikipedia's articles provide links to guide the user to related pages with additional information of them. Wikipedia has grown rapidly into one of the largest reference Web sites. There are more than 75,000 active contributors working on some 8,700,000 articles in more than 250 languages. Visitors are not requiered specialised qualifications to contribute, their primary role is to write articles that cover existing knowledge; meaning that people of all ages and cultural and social background can write Wikipedia articles. Be careful with articles, older articles tend to be more comprehensive and balanced, while newer articles more frequently contain significant misinformation, unencyclopedic content, or vandalism.