RSS is a family of XML file formats for web syndication used by news websites and weblogs. They are used to provide items containing short descriptions of web content together with a link to the full version of the content. This information is delivered as an XML file called RSS feed, webfeed, RSS stream, or RSS channel.
The acronym stands for one of the following standards:
- Rich Site Summary (RSS 0.91)
- RDF Site Summary (RSS 0.9 and 1.0)
- Really Simple Syndication (RSS 2.0)
Usage
RSS is widely used by the weblog community to share the latest entries' headlines or their full text, and even attached multimedia files. (See podcasting, broadcatching and MP3 blogs.)
The first online news site to use RSS feeds was Variety.com in June of 2002. In 2004 and 2005, after several years of use by early adopters, use of RSS spread to many major news organizations, including Reuters and the Associated Press. Under various usage agreements, providers allow other websites to incorporate their "syndicated" headline or headline-and-short-summary feeds.
A program known as a feed reader or aggregator can check RSS-enabled webpages on behalf of a user and display any updated articles that it finds. It is now common to find RSS feeds on major web sites, as well as many smaller ones.
Client-side readers and aggregators are typically constructed as standalone programs or extensions to existing programs like web browsers. See List of news aggregators for a list of clients for various operating systems.
Web-based feed readers and news aggregators require no software installation and make the user's "feeds" available on any computer with Web access. Some aggregators syndicate (combine) RSS feeds into new feeds, e.g. take all football related items from several sports feeds and provide a new football feed. There are also search engines for RSS feeds like Feedster, Technorati, Pluck or Plazoo.
RSS feeds are typically linked to with an orange rectangle with the letters XML () or RSS ().
History
RDF Site Summary (RSS) was originally designed by Dan Libby of Netscape in 1999 for use on the My Netscape portal. But RDF tools were in short supply, which caused it to be stripped of much of its semantic feature set. While the format was technically valid RDF, it dropped many of the features (such as namespaces) necessary for actual RDF use [1] (http://groups.yahoo.com/group/rss-dev/message/239).
In the meantime, Dave Winer of UserLand Software had already designed his own XML syndication format for use on his Scripting News weblog, which he had been using since 1997 [2] (http://davenet.scripting.com/1997/12/15/scriptingNewsInXML).
Winer began working with Netscape, and many of the ScriptingNews syndication format's features were incorporated into the next revision of RSS. The new RSS 0.91 was renamed Rich Site Summary and dropped the pretense of using RDF. This resulted in a simpler XML format that was incompatible with the earlier version.
Some time after this, Netscape's interest in RSS disappeared, and UserLand took over as de facto maintainers. UserLand released its own version of RSS 0.91 with several minor incompatible changes.
In 2000 RSS was split into two development paths[3] (http://www.xmlhack.com/read.php?item=621), one that favored modularization, and one that believed that the complexity of namespaces should be avoided.
In August of 2000, a group of developers organized in the rss-dev (http://groups.yahoo.com/group/rss-dev/) mailing list published a proposed specification for RSS 1.0 (http://purl.org/rss/1.0/) [4] (http://groups.yahoo.com/group/syndication/message/372). This format reintroduced the originally intended RDF and was designed to allow for extension through modules (http://purl.org/rss/1.0/modules/).