Google Knol is now open to all

What is Knol?
According to Google, Knol is a Goggle Project which aims to include user-written articles on topics ranging from “scientific concepts, to medical information, from geographical and historical, to entertainment, from product information, to how-to-fix-it instructions etc.
Its mainly the brainchild of Google vice president of engineering Udi Manber, it was announced on December 13, 2007 and was opened in beta to the public on July 23, 2008 with a few hundred articles.

Knol pages are “meant to be the first thing someone who searches for this topic for the first time will want to read”, according to Manber. The term knol, which Google defines as a “unit of knowledge”, refers to both the project and an article in the project. Several experts see Knol as Google’s attempt to compete with Wikipedia, while others point out the crucial differences between the projects.

At the time of its launch, Knol was seeded with several hundred articles, mostly in the health and medical field. All knols are licensed by default under a Creative Commons copyleft license, but authors may choose traditional copyright protections. It is unclear if this default license is compatible with the GFDL used in Wikipedia. All contributors must sign in first with a Google account. Knol has a content policy describing topics unacceptable for the project. Relevant nudity is allowed (in most countries), but pornography, commercial or otherwise, is forbidden. Also forbidden is discriminatory or violent content. Content designed to promote businesses, products or services is allowed, but articles devoid of substantive content and created solely to generate ad revenue are not.

Readers may rate, comment on, or suggest edits to the articles. There can also be multiple articles for the same topic, each written by a different author. Google “(believes) that knowing who wrote what will significantly help users make better use of web content.” Manber said that Google hopes “knols will include the opinions and points of view of the authors who will put their reputation on the line” and that the authors will be able to decide whether advertisements will appear on their knols, and that if there are ads, a “substantial revenue share from the proceeds of those ads” will be given to authors. Manber also writes that “Google will not serve as an editor in any way, and will not bless any content. All editorial responsibilities and control will rest with the authors.”

Like Wikipedia, Knol “nofollow” all outgoing links. Knol is using a meta directive in the head section of the HTML