A free content, multilingual encyclopedia written collaboratively by contributors around the world. The site is a Wiki - anybody can edit and add to an article. Offers quick understanding on controversial issues. Strong in current affairs.

About its history Wikipedia itself says:

Wikipedia began as a complementary project for Nupedia, a free online encyclopedia project whose articles were written by experts and reviewed by a formal process. Nupedia was founded on March 9, 2000, under the ownership of Bomis, Inc, a web portal company. Its principal figures were Jimmy Wales, Bomis CEO, and Larry Sanger, editor-in-chief for Nupedia and later Wikipedia. Nupedia was licensed initially under its own Nupedia Open Content License, switching to the GFDL before Wikipedia’s founding at the urging of Richard Stallman.

I see Wikipedia as one of the greatest resource on WWW. As usual there are some controversies and issues related with Wikipedia also, one of the major thing being reliability of the information.

Say whatever, Wikipedia rocks