After 6 months of beta testing, Google has invited everyone to participate in Knol - a new author-driven encyclopaedia service.

Announced in December 2007, Knol enables its users to contribute any number of Knol's, or "unit's of knowledge".

If you're a regular user of Wikipedia, you'll be aware of Knol's striking similarities. Wikipedia allows anyone to anonymously create and edit pages on any topic. Need to know about the history of Croatia, how to wire a plug or make a Christmas cake? - the Wikipedia community is sure to help. One downfall that has often been a point of debate with users is that its anonymity is open to vandalism.

While Knol has similarities to Wikipedia in it's concept, it has one major difference that relates to anonymity and authorship. "Every knol will have an author, or group of authors, who put their name behind their content. It's their knol, their voice, their opinion." posted Cedric Dupont, Product Manager and Michael McNally.

Once an article has been authored, by default they are set to use 'moderated collaboration', which basically means the article is open to modification but the edits will have to be approved by the original author before going live. "This allows authors to accept suggestions from everyone in the world while remaining in control of their content. After all, their name is associated with it!"

Contributers to Knol will be given the option of supporting Adwords Ads on their Knol. " If an author chooses to include ads, Google will provide the author with substantial revenue share from the proceeds of those ads."