Knol was a Google project that aimed to include user-written articles on a range of topics. The lower-case term knol, which Google defined as a "unit of knowledge", referred to an article in the project. Knol was often viewed as a rival to Wikipedia. The project was led by Udi Manber, a Google vice president of engineering. It was announced on December 13, 2007, and was opened in beta version on July 23, 2008, with a few hundred articles, mostly in the health and medical field. Knol did not find a significant audience and became viewed as a failure. The project was closed on April 30, 2012, and all content was deleted after October 1, 2012. The Internet Archive has snapshots of Knol archived between July 2008 and May 2012. More information...
According to PR-model, knol.google.com is ranked 32,180th in multilingual Wikipedia, in particular this website is ranked 29,336th in English Wikipedia.
The website is placed before luxvide.it and after vodafone.com in the BestRef global ranking of the most important sources of Wikipedia.