RSS is an XML-based vocabulary for distributing Web content in opt-in feeds. Feeds allow the user to have new content delivered to a computer or mobile device as soon as it is published. An RSS aggregator or RSS reader allows the user to see summaries of all their feeds in one place. Instead of visiting multiple Web pages to check for new content, the user can look at the summaries and choose which sites to visit for the full versions.
RSS is an abbreviation for describing one of three different standards, which include:
- RDF Site Summary (RSS .9 and 1.0)
- Rich Site Summary (RSS 0.91 and 1.0)
- Really Simple Syndication (RSS 2.0)
RSS adheres to the World Wide Web Consortium's (W3C) Resource Description Framework (RDF). Originally developed by Netscape for the Netcenter channels in its Web browser, Navigator, the RSS specification is now available for anyone to use.
To use RSS, any Web site that wants to "publish" some of its content, such as news headlines or stories, creates a description of the content and specifically where the content is on its site in the form of an RSS document. The publishing site then registers its RSS document with one of several existing directories of RSS publishers. Some current directories of RSS files include Meerkat, GropSoup, NewsIsFree, UserLand, and XML Tree; these sites are sometimes known as content aggregators. RSS browsers include Headline Viewer and Novobot. Internet Explorer 7 and Mozilla's Firefox 2.0 both include integrated RSS subscription functions. Users can see whether a Web site has RSS feeds by looking in the far right of the address field in the Web browser, to the right of the URL, and clicking on the universal RSS feed icon, shown on the right.
News is only one form of content that can be distributed with an RSS feed. Other possibilities include discussion forum excerpts, software announcements, blog posts, podcasts and any form of content retrievable with a URL. Listen to the podcast below to learn about all of the other different ways that RSS is being applied.
Atom (XML) is an alternative, open-source specification that provides similar functionality.