Del.icio.us is a social bookmarking web service for storing, sharing, and discovering web bookmarks. The site was founded by Joshua Schachter in late 2003, and was acquired by Yahoo! in 2005. Now it has more than three million users and 100 million bookmarked URLs.

General description

Del.icio.us uses a non-hierarchical keyword categorization system, in which users can tag each of their bookmarks with a number of freely chosen keywords (cf. folksonomy). A combined view of everyone's bookmarks with a given tag is available; for instance, the URL "http://del.icio.us/tag/wiki" displays all of the most recent links tagged "wiki". Its collective nature makes it possible to view bookmarks added by similar-minded users.

Del.icio.us has a "hotlist" on its home page and "popular" and "recent" pages, which help to surface interesting content and make the website an effective conveyor of popular internet memes and trends.

Many novel features have contributed to making Del.icio.us one of the most popular social bookmarking services. These consist of the website's simple interface, human-readable URL scheme, a novel domain name, a simple REST API, and RSS feeds for web syndication.

Use of Del.icio.us is free. The source code of the site is not available, but a user's own data is freely downloadable through the site's API in an XML or JSON format, and can also be exported to a standard Netscape bookmarks format.

Everything posted to Del.icio.us is publicly viewable by default, although a user can mark specific bookmarks as private, and imported bookmarks are private by default. The public aspect is emphasized; it is not focused on storing private ("not shared") bookmark collections. Many people use the Del.icio.us linkrolls, tagrolls and network badges to display their links and information on their weblogs. Others use the RSS feeds and daily blog posting feature to do this.

There are several competing social bookmarking services, such as Simpy, Furl and Netvouz, as well as a few open source clones.

Del.icio.us was acquired by Yahoo! on December 9, 2005. Various guesses suggest it was sold for somewhere between US$15 million and US$30 million.

The del.icio.us domain name is a notable example of a domain hack, an unconventional combination of letters to form a word or phrase. Del.icio.us, though not the first domain of this nature, is the best-known and most frequently-accessed domain hack, and the Yahoo! acquisition is the highest-profile acquisition of a domain in this category. However, delicious.com and delicio.us also redirect to the del.icio.us website.

As of August 2007, the BBC news web site supports social bookmarking links for its news and sport articles, including del.icio.us.

Name change

On September 6, 2007, Joshua Schachter said the website's name would change to "Delicious" when the site redesign was released, at an unspecifed date. The first letter will be uppercase in normal text and lowercase when displayed as a logo, and the domain name will be delicious.com.