Google has formally released to the public Knol, its alternative encyclopedia service to Wikipedia. Check out the page here at your own risk; it includes a lot of information about diseases. Thus far, Knol is a haven for doctors.
Google bills knols, announced last December, as units of knowledge. The service had been limited to invitations to contributors and readers to this point.
The company calls the service an act of "moderated collaboration," where "any reader can make suggested edits to a knol which the author may then choose to accept, reject, or modify before these contributions become visible to the public."
The idea is that the author may accept suggestions from anyone while remaining in control of their content. I love this notion; it creates a great crowdsourcing vibe to Knol. Check out these screen shot examples from ReadWriteWeb and this Google Blogoscoped post here.
Like a wiki, there are community tools, which allow for multiple modes of interaction between readers and authors. We users can comment on, rate or write a review of a knol. This isn't much different from the way we'd comment on Google Watch, TechCrunch or ReadWriteWeb.
It is very different from Wikipedia, which doesn't include moderation. Authors in Wikipedia write whatever they want. Search Engine Land's Danny Sullivan writes about the differences, as well as the similarities, in a detailed post here.
Moderation is important to keep posting vandals out. Presumably, you can't just write any old lie and get away with it.
Knol writers can make money, too. Authors may include ads related to knols from Google's AdSense program.
What I find really great is that Google has struck an agreement with the New Yorker magazine, which allows any author to add one cartoon per knol from the New Yorker's cartoon bank. This lends some serious humor to knol posts.
Knol won't be a Wikipedia killer any more than Yahoo or Microsoft will be a search killer to Google. There are simply too many Wikipedia users. I rely on Wikipedia as much as Google and wouldn't think of changing. But Knol is a cheap, easy service for Google to create, so why not do it?
I don't think too many users will join, with Wikipedia being so successful, but it's nice to have an alternative.
Where was this four years ago? Imagine if Jimmy Wales had cut his teeth at Google. That would be one super-powerful Wikipedia system.