ReadWriteWeb

Besides being the day that Macworld crashed Twitter, today was also Wikipedia's seventh birthday. In the 7 years since Wikipedia was publicly launched on January 15, 2001, the online encyclopedia has put up some impressive numbers. The flagship English language version now has 2,174,371 articles (as I write this), is the 9th most popular site on the Internet (according to Alexa), and has spawned 6 side projects (Wiktionary, Wikibooks, Wikinews, Wikiquote, Wikisource, and Wikiversity).

Wikipedia's projects span over 250 languages, with 9.4 million articles, 1.5 million images, and 10.3 million registered users (75,000 of whom are active contributors). All in the public domain.