Overview of all keyword tags in articles

Diigo is a social bookmarking website which allows signed-up users to bookmark and tag web-pages. Additionally, it allows users to highlight any part of a webpage and attach sticky notes to specific highlights or to a whole page. These annotations can be kept private, shared with a group within Diigo or a special link forwarded to someone else. The name "Diigo" is an acronym from "Digest of Internet Information, Groups and Other stuff". (Excerpt from <a href="http://en.wikipedia.org/wiki/Diigo">Wikipedia article: Diigo</a>)