Wikipedia is a Web-based, free-content encyclopedia written collaboratively by volunteers and sponsored by the non-profit Wikimedia Foundation. It contains entries both on traditional encyclopedic topics and on almanac, gazetteer, and current events topics. Its purpose is to create and distribute a free international encyclopedia in as many languages as possible. Wikipedia is the most popular reference site on the internet, receiving tens of millions hits per day.

The English section of Wikipedia has over 2 million articles and is growing fast. It is edited by volunteers in wiki fashion, meaning articles are subject to change by nearly anyone. Wikipedia's volunteers enforce a policy of "neutral point of view" whereby views presented about notable persons or literature are summarized without an attempt to determine an objective truth. Because of its open nature, vandalism and inaccuracy are problems in Wikipedia.

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London London is the capital city of the United Kingdom and of England. It produces 17% of the UK's GDP and the City of London is one of the world's major financial centres. The former capital of a global empire, London is pre-eminent in the culture, communications, politics, finance, and arts of its country, and has considerable influence worldwide. Alongside New York City, Paris, and Tokyo, London is often listed among the four major global cities. The estimated population, as of 1 January 2005, was 7,421,228 in Greater London, and several million more in London's metropolitan area(see the Demographics section below), easily making London the largest city in the UK. Its population includes a very diverse range of peoples, cultures, and religions, making it one of the most cosmopolitancities in Europe, and the world. Many of the world's wealthiest people are also permanent or temporary residents. More...		Mathematical and Natural Sciences Astronomy - Biology - Chemistry - Computer science - Earth science - Ecology - Health science - Mathematics - Physics - Statistics Applied Arts and Sciences Agriculture - Architecture - Business - Communication- Education - Engineering - Family and consumer science - Government - Law - Library and information science- Medicine - Politics - Public affairs - Software engineering - Technology - Transport Social Sciences and Philosophy Anthropology - Archaeology - Economics - Geography - History - History of science and technology - Language - Linguistics - Mythology - Philosophy - Political science - Psychology - Sociology Culture and Fine Arts Classics - Cooking - Dance - Entertainment - Film - Games - Gardening - Handicraft - Hobbies - Holidays - Internet - Literature - Music - Opera - Painting - Poetry - Radio - Recreation - Religion - Sculpture - Sports - Television - Theater - Tourism - Visual arts and design Other Category Schemes By category - By academic discipline - Historical timeline - Themed timelines - Calendar - Reference tables - Biographies - Countries