Diigo is an acronym for “Digest of Internet Information, Groups and Other stuff.”
It is a social bookmarking program that allows saving ‘favourites’ online, so that they can be accessible from any computer with an internet connection. However, Diigo does much more than this.
As something is being read on the web, along with bookmarking websites, you can also highlight parts of web pages that are of particular interest to you. Or, you can attach sticky notes to specific parts of web pages. These highlights and sticky notes are persistent – whenever you return to the original web page, you will see your highlights and sticky notes superimposed on the original page, just what you would expect if you highlighted or wrote on a book!
All Diigo user tagging and annotating pages online has collectively created a wonderful repository of quality content, filtered and annotated by the community, on almost any subject.