Wikipedia: Who knows?

It has no editors, no fact checkers and anyone can contribute an entry - or delete one. It should have been a recipe for disaster, but instead Wikipedia became one of the internet's most inspiring success stories.

There have been no shortage of insane, over ambitious ideas on the internet. Most of them never make it further than the pub they are conceived in. Some generate hype but quickly fall flat on their face. Others survive, but prove to be minnows rather than the giants they set out to be. However, every so often, one sneaks through.

The Guardian on Wikipedia.