|File name extension|
|Internet media type|
RSS is a family of Web feed formats used to publish frequently updated content such as blog entries, news headlines, and podcasts in a standardized format. An Internet media type, originally called a MIME type after MIME and sometimes a Content-type after the name of a header in several protocols whose value Don't change "Extensible" A web feed (or news feed) is a data format used for providing users with frequently updated content A blog (a contraction of the term " Web log " is a Web site, usually maintained by an individual with regular entries of commentary descriptions of A podcast is a series of audio or Video digital-media files which is distributed over the Internet by syndicated Download  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 web sites in an automated manner that can be piped into special programs or filtered displays. 
The benefit of RSS is the aggregation of content from multiple Web sources in one place. RSS content can be read using software called an "RSS reader", "feed reader" or an "aggregator", which can be web-based or desktop-based. In computing a feed aggregator, also known as a feed reader, news reader or simply aggregator, is client software or a Web application In Software engineering, a web application or webapp is an application that is accessed via Web browser over a network such as the Internet Application software is a subclass of Computer software that employs the capabilities of a computer directly and thoroughly to a task that the user wishes to perform A standardized XML file format allows the information to be published once and viewed by many different programs. Don't change "Extensible" 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 RSS reader checks the user's subscribed feeds regularly for new content, downloading any updates that it finds and provides a user interface to monitor and read the feeds. The user interface (or Human Computer Interface) is the aggregate of means by which people&mdash the users '&mdash interact with the System
The initials "RSS" are used to refer to the following formats:
RSS formats are specified using XML, a generic specification for the creation of data formats. Don't change "Extensible" Although RSS formats have evolved since March 1999, the RSS icon ("") first gained widespread use in 2005/2006.
The RSS formats were preceded by several attempts at syndication that did not achieve widespread popularity. Safari is a Web browser developed by Apple Inc and included in Mac OS X. Web syndication is a form of syndication in which Website material is made available to multiple other sites 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). Ramanathan V Guha (1965 is an Indian computer scientist. He graduated from Indian Institute of Technology Madras. Apple Inc, ( formerly Apple Computer Inc, is an American Multinational corporation with a focus on designing and manufacturing Consumer electronics Meta Content Framework ( MCF) was a specification of a format for structuring Metadata about Web sites and other Data.  For a more detailed discussion of these early developments, see the history of web syndication technology. This article is specifically dedicated to the history of web syndication technology and more generally to the history of technical innovation on many dialects of web syndication
RDF Site Summary, the first version of RSS, was created by Guha at Netscape in March 1999 for use on the My. Ramanathan V Guha (1965 is an Indian computer scientist. He graduated from Indian Institute of Technology Madras. Netscape Communications (formerly known as Netscape Communications Corporation and commonly known as Netscape) is an American computer services company 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. The Resource Description Framework (RDF is a family of World Wide Web Consortium (W3C Specifications originally designed as a Metadata Data Dave Winer (born May 2, 1955 in Brooklyn, New York City, USA) is an American software developer and entrepreneur in  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, with neither Netscape's help nor 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. The RSS-DEV Working Group was the outgrowth of a fork in RSS format development UserLand Software is a US Software company founded by Dave Winer in 1988.
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 United States Patent and Trademark Office ( PTO or USPTO) is an agency in the United States Department of Commerce that issues Patents to 
The RSS-DEV Working Group, a project whose members included Guha and representatives of O'Reilly Media and Moreover, produced RSS 1. O'Reilly Media (formerly O'Reilly & Associates) is an American media company established by Tim O'Reilly 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. XML namespaces are used for providing uniquely named elements and attributes in an XML instance The Dublin Core Metadata element set is a standard for cross-domain information resource description
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. A podcast is a series of audio or Video digital-media files which is distributed over the Internet by syndicated Download 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 an alternative syndication format, Atom, that began in June 2003. The name Atom applies to a pair of related standards The Atom Syndication Format is an XML language used for Web feeds while the Atom Publishing 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 IETF Proposed Standard RFC 4287.
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. Harvard Law School (also known as Harvard Law or HLS) is one of the professional Graduate schools of Harvard University.  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. The RSS Advisory Board is a group founded in July 2003 that publishes the RSS 0 NetNewsWire is a Freeware desktop News aggregator for Mac OS X, featuring a three-paned interface similar to Apple 's Mail client Jon Udell is an "Evangelist" at Microsoft. Previously he was lead analyst for the InfoWorld Test Center 
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 web browser is a software application which enables a user to display and interact with text images videos music games and other information typically located on a A few months later, Opera Software followed suit. Opera Software ( is a Norwegian corporation primarily known for its Opera family of web browsers 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, Rogers Cadenhead relaunched the RSS Advisory Board without Dave Winer's participation, with a stated desire to continue the development of the RSS format and resolve ambiguities. January 2006: ← - January - February - March - April - May - June - July Rogers Cadenhead (b April 13, 1967 in Dallas, Texas, USA) is a computer book author and web publisher who is currently chairman of The RSS Advisory Board is a group founded in July 2003 that publishes the RSS 0 Dave Winer (born May 2, 1955 in Brooklyn, New York City, USA) is an American software developer and entrepreneur in In June 2007, the board revised their version of the specification to confirm that namespaces may extend core elements with namespace attributes, as Microsoft has done in Internet Explorer 7. In their view, a difference of interpretation left publishers unsure of whether this was permitted or forbidden.
As noted above, there are several different versions of RSS, falling into two major branches (RDF and 2. *). The RDF, or RSS 1. * branch includes the following versions:
The RSS 2. * branch (initially UserLand, now Harvard) includes the following versions:
For the most part, later versions in each branch are backward-compatible with earlier versions (aside from non-conformant RDF syntax in 0. 90), and both versions include properly documented extension mechanisms using XML Namespaces, either directly (in the 2. * branch) or through RDF (in the 1. * branch). Most syndication software supports both branches. Mark Pilgrim's article "The Myth of RSS Compatibility" discusses RSS version compatibility in more detail.
The extension mechanisms make it possible for each branch to track innovations in the other. For example, the RSS 2. * branch was the first to support enclosures, making it the current leading choice for podcasting, and as of mid-2005 is the format supported for that use by iTunes and other podcasting software; however, an enclosure extension is now available for the RSS 1. RSS enclosures are a way of attaching Multimedia content to RSS feeds by providing the URL of a file associated with an entry such as an A podcast is a series of audio or Video digital-media files which is distributed over the Internet by syndicated Download iTunes is a proprietary digital media player application introduced by Apple Inc A podcast is a series of audio or Video digital-media files which is distributed over the Internet by syndicated Download * branch, mod_enclosure. Likewise, the RSS 2. * core specification does not support providing full-text in addition to a synopsis, but the RSS 1. * markup can be (and often is) used as an extension. There are also several common outside extension packages available, including a new proposal from Microsoft for use in Internet Explorer 7. Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer Windows Internet Explorer (formerly Microsoft Internet Explorer abbreviated MSIE) commonly abbreviated to IE, is a series of graphical
The most serious compatibility problem is with HTML markup. Userland's RSS reader—generally considered as the reference implementation—did not originally filter out HTML markup from feeds. HTML, an initialism of HyperText Markup Language, is the predominant Markup language for Web pages It provides a means to describe the structure As a result, publishers began placing HTML markup into the titles and descriptions of items in their RSS feeds. This behavior has become expected of readers, to the point of becoming a de facto standard, though there is still some inconsistency in how software handles this markup, particularly in titles. The RSS 2. 0 specification was later updated to include examples of entity-encoded HTML; however, all prior plain text usages remain valid.
The primary objective of all RSS modules is to extend the basic XML schema established for more robust syndication of content. Don't change "Extensible" This inherently allows for more diverse, yet standardized, transactions without modifying the core RSS specification.
To accomplish this extension, a tightly controlled vocabulary (in the RSS world, "module"; in the XML world, "schema") is declared through an XML namespace to give names to concepts and relationships between those concepts. XML namespaces are used for providing uniquely named elements and attributes in an XML instance
Some RSS 2. 0 modules with established namespaces:
Several BitTorrent-based peer-to-peer applications also support RSS. BitTorrent is a Peer-to-peer File sharing protocol used to distribute large amounts of Data. For other uses of the term see Peer-to-peer (disambiguation For peer-to-peer networks used for file sharing see File sharing Such feeds (also known as Torrent/RSS-es or Torrentcasts) allow client applications to download files automatically from the moment the RSS reader detects them (also known as Broadcatching). Broadcatching is the downloading of digital content that has been made available over the Internet using RSS syndication
The following is an example of an RSS 1. 0 file (the quoted strings are in red font).
<?xml version="1. 0"?> <rdf:RDF xmlns:rdf="http://www. w3. org/1999/02/22-rdf-syntax-ns#" xmlns="http://purl. org/rss/1. 0/"> <channel rdf:about="http://www. xml. com/xml/news. rss"> <title>XML. com</title> <link>http://xml. com/pub</link> <description> XML. com features a rich mix of information and services for the XML community. </description> <image rdf:resource="http://xml. com/universal/images/xml_tiny. gif" /> <items> <rdf:Seq> <rdf:li rdf:resource="http://xml. com/pub/2000/08/09/xslt/xslt. html" /> <rdf:li rdf:resource="http://xml. com/pub/2000/08/09/rdfdb/index. html" /> </rdf:Seq> </items> <textinput rdf:resource="http://search. xml. com" /> </channel> <image rdf:about="http://xml. com/universal/images/xml_tiny. gif"> <title>XML. com</title> <link>http://www. xml. com</link> <url>http://xml. com/universal/images/xml_tiny. gif</url> </image> <item rdf:about="http://xml. com/pub/2000/08/09/xslt/xslt. html"> <title>Processing Inclusions with XSLT</title> <link>http://xml. com/pub/2000/08/09/xslt/xslt. html</link> <description> Processing document inclusions with general XML tools can be problematic. This article proposes a way of preserving inclusion information through SAX-based processing. </description> </item> <item rdf:about="http://xml. com/pub/2000/08/09/rdfdb/index. html"> <title>Putting RDF to Work</title> <link>http://xml. com/pub/2000/08/09/rdfdb/index. html</link> <description> Tool and API support for the Resource Description Framework is slowly coming of age. Edd Dumbill takes a look at RDFDB, one of the most exciting new RDF toolkits. </description> </item> <textinput rdf:about="http://search. xml. com"> <title>Search XML. com</title> <description>Search XML. com's XML collection</description> <name>s</name> <link>http://search. xml. com</link> </textinput></rdf:RDF>
The following is an example of an RSS 2. 0 file (strings in red font).
<?xml version="1. 0"?><rss version="2. 0"> <channel> <title>Lift Off News</title> <link>http://liftoff. msfc. nasa. gov/</link> <description>Liftoff to Space Exploration. </description> <language>en-us</language> <pubDate>Tue, 10 Jun 2003 04:00:00 GMT</pubDate> <lastBuildDate>Tue, 10 Jun 2003 09:41:01 GMT</lastBuildDate> <docs>http://blogs. law. harvard. edu/tech/rss</docs> <generator>Weblog Editor 2. 0</generator> <managingEditor>editor@example. com</managingEditor> <webMaster>webmaster@example. com</webMaster> <ttl>5</ttl> <item> <title>Star City</title> <link>http://liftoff. msfc. nasa. gov/news/2003/news-starcity. asp</link> <description>How do Americans get ready to work with Russians aboard the International Space Station? They take a crash course in culture, language and protocol at Russia's Star City. </description> <pubDate>Tue, 03 Jun 2003 09:39:21 GMT</pubDate> <guid>http://liftoff. msfc. nasa. gov/2003/06/03. html#item573</guid> </item> <item> <title>Space Exploration</title> <link>http://liftoff. msfc. nasa. gov/</link> <description>Sky watchers in Europe, Asia, and parts of Alaska and Canada will experience a partial eclipse of the Sun on Saturday, May 31st. </description> <pubDate>Fri, 30 May 2003 11:06:42 GMT</pubDate> <guid>http://liftoff. msfc. nasa. gov/2003/05/30. html#item572</guid> </item> <item> <title>The Engine That Does More</title> <link>http://liftoff. msfc. nasa. gov/news/2003/news-VASIMR. asp</link> <description>Before man travels to Mars, NASA hopes to design new engines that will let us fly through the Solar System more quickly. The proposed VASIMR engine would do that. </description> <pubDate>Tue, 27 May 2003 08:37:32 GMT</pubDate> <guid>http://liftoff. msfc. nasa. gov/2003/05/27. html#item571</guid> </item> <item> <title>Astronauts' Dirty Laundry</title> <link>http://liftoff. msfc. nasa. gov/news/2003/news-laundry. asp</link> <description>Compared to earlier spacecraft, the International Space Station has many luxuries, but laundry facilities are not one of them. Instead, astronauts have other options. </description> <pubDate>Tue, 20 May 2003 08:56:02 GMT</pubDate> <guid>http://liftoff. msfc. nasa. gov/2003/05/20. html#item570</guid> </item> </channel></rss>
The following tag should be placed into the head of an XHTML document to provide a link to an RSS Feed.
<link href="rss. xml" rel="alternate" type="application/rss+xml" title="Sitewide RSS Feed" />