|Type of site||Social Annotations, Highlighting and Social Bookmarking|
|Launched||July 4, 2006|
Diigo (pron.: //) 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".
Premium account holders can perform full-text searches of cached copies of bookmarks. A full-text search also searches page URLs, tags and annotations. This means that premium account holders can choose to omit tags that already appear in the text of a page to be bookmarked (although text inside images cannot be searched).
Outside the website, Diigo's graphical user interface includes an optional bookmarklet, or a customizable toolbar, with various search capabilities. Highlight is enabled by a menu, that can either appear automatically when content is selected, or be embedded into the context menu.
On October 25, 2012, the diigo.com domain was hijacked. An unknown attacker changed the authoritative nameserver records ("NS records") for DNS zone DIIGO.COM, temporarily giving control to nameservers at AFRAID.ORG, and causing traffic to be misdirected. 
See also 
- ShiftSpace, an open-source web annotation framework for Firefox
- Reframe It, a free commenting plug-in compatible with multiple browsers
- Diigo V4: Research ~ annotate, archive, organize (flash) (Presentation). Diigo. 2009-09-24. Event occurs at 0:00.
- Diigo is about Social Annotation
- "Full text search - diigo help". Retrieved 28 October 2010.
- Diigo Launches, Nobody Cares
- Diigo Offers "Social Annotation" Tool - Search Engine Watch
- Get smart: Top 10 research tools - Internet