From Chewiki: 1% Funny, 99% Hot Gas
What Is It?
An online encyclopedia that any user, anonymous or logged into an account, can edit (except on pages that are protected/semi-protected). It runs on some engine called "MediaWiki", who's logo is pretty much some big flower with brackets around it.
Wikipedia has recently changed its default layout, resulting in backlash.
How It Came To Be
Wikipedia was created by James "Jimbo" Wales. He created it because he wanted to create a compilation of all the knowledge in the world. This is despite the fact that he rejects things he considers "not notable". It is believed that an overdose on information compiled on Wikipedia may greatly expand one's vocabulary to astronomical levels, possibly to the irritation of the flesh creatures around yourself.
Wikipedia is subject to various vandalism. Don't believe us? Check through the Recent Changes page there...if you can keep up. Seriously, those guys are quick bastards.