RSS (formally "RDF Site Summary", known colloquially as "Really Simple Syndication") is a family of Web feed formats used to publish frequently updated content such as blog entries, news headlines or podcasts. An RSS document, which is called a "feed", "web feed", or "channel", contains either a summary of content from an associated web site or the full text. RSS makes it possible for people to keep up with their favorite web sites in an automated manner that's easier than checking them manually.
RSS content can be read using software called an "RSS reader", "feed reader" or an "aggregator". The user subscribes to a feed by entering the feed's link into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The reader checks the user's subscribed feeds regularly for new content, downloading any updates that it finds.
The initials "RSS" are used to refer to the following formats:
Really Simple Syndication (RSS 2.0)
RDF Site Summary (RSS 1.0 and RSS 0.90)
Rich Site Summary (RSS 0.91)
RSS formats are specified using XML, a generic specification for the creation of data formats.
The RSS formats were preceded by several attempts at syndication that did not achieve widespread popularity. The basic idea of restructuring information about web sites goes back to as early as 1995, when Ramanathan V. Guha and others in Apple Computer's Advanced Technology Group developed the Meta Content Framework (MCF). For a more detailed discussion of these early developments, see the history of web syndication technology.
RDF Site Summary, the first version of RSS, was created by Guha at Netscape in March 1999 for use on the My.Netscape.Com portal. This version became known as RSS 0.9. In July 1999, Dan Libby of Netscape produced a new version, RSS 0.91, that simplified the format by removing RDF elements and incorporating elements from Dave Winer's scriptingNews syndication format. Libby also renamed RSS to Rich Site Summary and outlined further development of the format in a "futures document".
This would be Netscape's last participation in RSS development for eight years. As RSS was being embraced by web publishers who wanted their feeds to be used on My.Netscape.Com and other early RSS portals, Netscape dropped RSS support from My.Netscape.Com in April 2001 during new owner AOL's restructuring of the company, also removing documentation and tools that supported the format.
Two entities emerged to fill the void, neither with Netscape's help or approval: The RSS-DEV Working Group and Winer, whose UserLand Software had published some of the first publishing tools outside of Netscape that could read and write RSS.
Winer published a modified version of the RSS 0.91 specification on the UserLand web site, covering how it was being used in his company's products, and claimed copyright to the document. A few months later, UserLand filed a U.S. trademark registration for RSS, but failed to respond to a USPTO trademark examiner's request and the request was rejected in December 2001.
The RSS-DEV Working Group, a project whose members included Guha and representatives of O'Reilly Media and Moreover, produced RSS 1.0 in December 2000. This new version, which reclaimed the name RDF Site Summary from RSS 0.9, reintroduced support for RDF and added XML namespaces support, adopting elements from standard metadata vocabularies such as Dublin Core.
In December 2000, Winer released RSS 0.92 a minor set of changes aside from the introduction of the enclosure element, which permitted audio files to be carried in RSS feeds and helped spark podcasting. He also released drafts of RSS 0.93 and RSS 0.94 that were subsequently withdrawn.
In September 2002, Winer released a major new version of the format, RSS 2.0, that redubbed its initials Really Simple Syndication. RSS 2.0 removed the type attribute added in the RSS 0.94 draft and added support for namespaces.
Because neither Winer nor the RSS-DEV Working Group had Netscape's involvement, they could not make an official claim on the RSS name or format. This has fueled ongoing controversy in the syndication development community as to which entity was the proper publisher of RSS.
One product of that contentious debate was the creation of a rival syndication format, Atom, that began in June 2003. The Atom syndication format, whose creation was in part motivated by a desire to get a clean start free of the issues surrounding RSS, has been adopted as an IETF standard.
In July 2003, Winer and UserLand Software assigned the copyright of the RSS 2.0 specification to Harvard's Berkman Center for the Internet & Society, where he had just begun a term as a visiting fellow. At the same time, Winer launched the RSS Advisory Board with Brent Simmons and Jon Udell, a group whose purpose was to maintain and publish the specification and answer questions about the format.
In December 2005, the Microsoft Internet Explorer team and Outlook team announced on their blogs that they were adopting the feed icon first used in the Mozilla Firefox browser . A few months later, Opera Software followed suit. This effectively made the orange square with white radio waves the industry standard for RSS and Atom feeds, replacing the large variety of icons and text that had been used previously to identify syndication data.
In January 2006, RSS Advisory Board chairman Rogers Cadenhead announced that eight new members had joined the group, continuing the development of the RSS format and resolving ambiguities in the RSS 2.0 specification. Netscape developer Chris Finke joined the board in March 2007, the company's first involvement in RSS since the publication of RSS 0.91. In June 2007, the board revised its version of the specification to confirm that namespaces may extend core elements with namespace attributes, as Microsoft has done in Internet Explorer 7. In its view, a difference of interpretation left publishers unsure of whether this was permitted or forbidden.
Instant messaging (IM) is a form of real-time communication between two or more people based on typed text. The text is conveyed via computers connected over a network such as the Internet.