Google just opened up Knol, its Wikipedia competitor, to the public after announcing a private beta of the service last December. Unlike Wikipedia, Knol puts a stronger emphasis on authorship and even encourages users to start different 'knols' for the same subject. Google is also serving up AdSense advertising on the site, whereas Wikipedia stays away from any advertising on its site.

In many respects, Knol is similar to Jason Calacanis' Mahalo, though its scope seems even more ambitious and its tools a bit more refined. It does, however, validate the Mahalo model.

Knol puts a lot of emphasis on authorship and, somewhat akin to Amazon's "Real Name" scheme, authors can validate their identity on Knol through either a credit card or phone number.

The default setting for every Knol is "moderated collaboration." In this mode, anybody with a Google account can suggest changes to an knol, but the author has to accept these changes before they go live.

Authors can also invite others to contribute to their articles and given them the same Read the full article