On Sunday, 15 January, Wikipedia celebrated its fifth anniversary. Wikipedia was made public on 15 January, 2001, after spending five days of development and testing on Nupedia. The date has been known as Wikipedia Day ever since the one-year anniversary in 2002, although unlike other Wikipedia holidays, the holiday has never been officially proclaimed by Wikipedia founder Jimbo Wales.

The English Wikipedia now has 920 thousand articles (not including redirects), over 340 million words, and 720 thousand registered users, along with nearly 800 administrators. Globally, Wikipedia now has over three million distinct articles in over 200 languages.

Wikipedia entered the top 20 of Alexa rankings this year, and also increased the number of servers by 129, bringing the total number of servers up to 171, located primarily in Tampa. Other server clusters are in Amsterdam, Paris, and Seoul.

The site celebrated with a notice on the main page, Community Portal, site notice (along with a continued appeal for donations), and the top of the recent changes page.