RSS (RDF Site Summary or Really Simple Syndication)[2] is a web feed[3] that allows users and applications to access updates to websites in a standardized, computer-readable format. Subscribing to RSS feeds can allow a user to keep track of many different websites in a single news aggregator, which constantly monitor sites for new content, removing the need for the user to manually check them. News aggregators (or "RSS readers") can be built into a browser, installed on a desktop computer, or installed on a mobile device.
Websites usually use RSS feeds to publish frequently updated information, such as blog entries, news headlines, episodes of audio and video series, or for distributing podcasts. An RSS document (called "feed", "web feed",[4] or "channel") includes full or summarized text, and metadata, like publishing date and author's name. RSS formats are specified using a generic XML file.
Although RSS formats have evolved from as early as March 1999,[5] it was between 2005 and 2006 when RSS gained widespread use, and the ("") icon was decided upon by several major web browsers.[6] RSS feed data is presented to users using software called a news aggregator and the passing of content is called web syndication. Users subscribe to feeds either by entering a feed's URI into the reader or by clicking on the browser's feed icon. The RSS reader checks the user's feeds regularly for new information and can automatically download it, if that function is enabled.
History
This section needs to be updated. Please help update this article to reflect recent events or newly available information.(October 2013)
RDF Site Summary, the first version of RSS, was created by Dan Libby and Ramanathan V. Guha at Netscape. It was released in March 1999 for use on the My.Netscape.Com portal.[8] This version became known as RSS 0.9.[5] In July 1999, Dan Libby of Netscape produced a new version, RSS 0.91,[3] which simplified the format by removing RDF elements and incorporating elements from Dave Winer's news syndication format.[9] Libby also renamed the format from RDF to RSS Rich Site Summary and outlined further development of the format in a "futures document".[10]
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.[11]
Two parties emerged to fill the void, with neither Netscape's help nor approval: The RSS-DEV Working Group and Dave Winer, whose UserLand Software had published some of the first publishing tools outside Netscape that could read and write RSS.
Winer published a modified version of the RSS 0.91 specification on the UserLand website, covering how it was being used in his company's products, and claimed copyright to the document.[12] 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.[13]
The RSS-DEV Working Group, a project whose members included Aaron Swartz,[14] Guha and representatives of O'Reilly Media and Moreover, produced RSS 1.0 in December 2000.[15] 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[16] 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.[17]
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. To preserve backward compatibility with RSS 0.92, namespace support applies only to other content included within an RSS 2.0 feed, not the RSS 2.0 elements themselves.[18] (Although other standards such as Atom attempt to correct this limitation, RSS feeds are not aggregated with other content often enough to shift the popularity from RSS to other formats having full namespace support.)
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[specify] 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.[19] 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 RFC4287.
In July 2003, Winer and UserLand Software assigned the copyright of the RSS 2.0 specification to Harvard's Berkman Klein Center for Internet & Society, where he had just begun a term as a visiting fellow.[20] 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.[21]
In December 2005, the Microsoft Internet Explorer team[6] and Microsoft Outlook team[23] announced on their blogs that they were adopting Firefox's RSS icon. In February 2006, Opera Software followed suit.[24] 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. 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. According to their view, a difference of interpretation left publishers unsure of whether this was permitted or forbidden.
Example
RSS is XML-formatted plain text. The RSS format itself is relatively easy to read both by automated processes and by humans alike. An example feed could have contents such as the following:
User interface of an RSS feed reader on a desktop computer
When retrieved, RSS reading software could use the XML structure to present a neat display to the end users. There are various news aggregator software for desktop and mobile devices, but RSS can also be built-in inside web browsers or email clients like Mozilla Thunderbird.
Variants
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:
RSS 0.90 was the original Netscape RSS version. This RSS was called RDF Site Summary, but was based on an early working draft of the RDF standard, and was not compatible with the final RDF Recommendation.
RSS 1.0 is an open format by the RSS-DEV Working Group, again standing for RDF Site Summary. RSS 1.0 is an RDF format like RSS 0.90, but not fully compatible with it, since 1.0 is based on the final RDF 1.0 Recommendation.
RSS 1.1 is also an open format and is intended to update and replace RSS 1.0. The specification is an independent draft not supported or endorsed in any way by the RSS-Dev Working Group or any other organization.
The RSS 2.* branch (initially UserLand, now Harvard) includes the following versions:
RSS 0.91 is the simplified RSS version released by Netscape, and also the version number of the simplified version originally championed by Dave Winer from Userland Software. The Netscape version was now called Rich Site Summary; this was no longer an RDF format, but was relatively easy to use.
RSS 0.92 through 0.94 are expansions of the RSS 0.91 format, which are mostly compatible with each other and with Winer's version of RSS 0.91, but are not compatible with RSS 0.90.
RSS 2.0.1 has the internal version number 2.0. RSS 2.0.1 was proclaimed to be "frozen", but still updated shortly after release without changing the version number. RSS now stood for Really Simple Syndication. The major change in this version is an explicit extension mechanism using XML namespaces.[25]
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. "The Myth of RSS Compatibility", an article written in 2004 by RSS critic and Atom advocate Mark Pilgrim, discusses RSS version compatibility issues in more detail.
The extension mechanisms make it possible for each branch to copy 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 2005[update] is the format supported for that use by iTunes and other podcasting software; however, an enclosure extension is now available for the RSS 1.* 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, e.g. one from Microsoft for use in Internet Explorer 7.
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. 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.[26] 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.
As of January2007[update], tracking data from www.syndic8.com indicates that the three main versions of RSS in current use are 0.91, 1.0, and 2.0, constituting 13%, 17%, and 67% of worldwide RSS usage, respectively.[27] These figures, however, do not include usage of the rival web feed format Atom. As of August2008[update], the syndic8.com website is indexing 546,069 total feeds, of which 86,496 (16%) were some dialect of Atom and 438,102 were some dialect of RSS.[28]
Modules
The primary objective of all RSS modules is to extend the basic XML schema established for more robust syndication of content. 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.
Some RSS 2.0 modules with established namespaces are:
Although the number of items in an RSS channel is theoretically unlimited, some news aggregators do not support RSS files larger than 150KB. For example, applications that rely on the Common Feed List of Windows might handle such files as if they were corrupt, and not open them. Interoperability can be maximized by keeping the file size under this limit.
Podcasts are distributed using RSS. To listen to a podcast, a user adds the RSS feed to their podcast client, and the client can then list available episodes and download or stream them for listening or viewing. To be included in a podcast directory the feed must for each episode provide a title, description, artwork, category, language, and explicit rating. There are some services that specifically indexes and is a search engine for podcasts.[29]
Some services deliver RSS to an email inbox, sending updates from user's personal selection and schedules. Examples of such services include IFTTT, Zapier and others.[30] Conversely, some services deliver email to RSS readers.[31] Further services like e. g. Gmane allow to subscribe to feeds via NNTP.
Both RSS and Atom are widely supported and are compatible with all major consumer feed readers. RSS gained wider use because of early feed reader support. Technically, Atom has several advantages: less restrictive licensing, IANA-registered MIME type, XML namespace, URI support, RELAX NG support.[33]
The following table shows RSS elements alongside Atom elements where they are equivalent.
Note: the asterisk character (*) indicates that an element must be provided (Atom elements "author" and "link" are only required under certain conditions).
Several major sites such as Facebook and Twitter previously offered RSS feeds but have reduced or removed support. Additionally, widely used readers such as Shiira, FeedDemon, and particularly Google Reader, have all been discontinued as of 2013, citing declining popularity in RSS.[34] RSS support was removed in OS X Mountain Lion's versions of Mail and Safari, although the features were partially restored in Safari 8.[35][36] Mozilla removed RSS support from Mozilla Firefox version 64.0, joining Google Chrome and Microsoft Edge which do not include RSS support, thus leaving Internet Explorer as the last major browser to include RSS support by default.[37][38]
Since the late 2010s there has been an uptick in RSS interest again. In 2018, Wired published an article named "It's Time for an RSS Revival", citing that RSS gives more control over content compared to algorithms and trackers from social media sites. At that time, Feedly was the most popular RSS reader.[39] Chrome on Android has added the ability to follow RSS feeds as of 2021.[40]
Dave Winer is an American software developer, entrepreneur, and writer who resides in New York City. Winer is noted for his contributions to outliners, scripting, content management, and web services, as well as blogging and podcasting. He is the founder of the software companies Living Videotext, Userland Software and Small Picture Inc., a former contributing editor for the Web magazine HotWired, the author of the Scripting News weblog, a former research fellow at Harvard Law School, and current visiting scholar at New York University's Arthur L. Carter Journalism Institute.
Gecko is a browser engine developed by Mozilla. It is used in the Firefox browser, the Thunderbird email client, and many other projects.
The Resource Description Framework (RDF) is a World Wide Web Consortium (W3C) standard originally designed as a data model for metadata. It has come to be used as a general method for description and exchange of graph data. RDF provides a variety of syntax notations and data serialization formats, with Turtle currently being the most widely used notation.
UserLand Software is a US-based software company, founded in 1988, that sells web content management, as well as blogging software packages and services.
Web syndication is making content available from one website to other sites. Most commonly, websites are made available to provide either summaries or full renditions of a website's recently added content. The term may also describe other kinds of content licensing for reuse.
The name Atom applies to a pair of related Web standards. The Atom Syndication Format is an XML language used for web feeds, while the Atom Publishing Protocol is a simple HTTP-based protocol for creating and updating web resources.
OPML is an XML format for outlines. Originally developed by UserLand Software as a native file format for the outliner application in its Radio UserLand product, it has since been adopted for other uses, the most common being to exchange lists of web feeds between web feed aggregators.
On the World Wide Web, a web feed is a data format used for providing users with frequently updated content. Content distributors syndicate a web feed, thereby allowing users to subscribe a channel to it by adding the feed resource address to a news aggregator client. Users typically subscribe to a feed by manually entering the URL of a feed or clicking a link in a web browser or by dragging the link from the web browser to the aggregator, thus "RSS and Atom files provide news updates from a website in a simple form for your computer."
Meta Content Framework (MCF) is a specification of a content format for structuring metadata about web sites and other data.
Liferea is a news aggregator for online news feeds and podcasts. It supports the major feed formats including RSS/RDF and Atom and can import and export subscription lists in OPML format. Liferea is intended to be a fast, easy to use, and easy to install news aggregator for GTK+ that can be used with the GNOME desktop. Liferea features a script manager, in which users can add custom scripts that run whenever a certain action occurs.
Channel Definition Format (CDF) was an XML file format formerly used in conjunction with Microsoft's Active Channel, Active Desktop and Smart Offline Favorites technologies. The format was designed to "offer frequently updated collections of information, or channels, from any web server for automatic delivery to compatible receiver programs." Active Channel allowed users to subscribe to channels and have scheduled updates delivered to their desktop. Smart Offline Favorites, like channels, enabled users to view webpages from the cache.
OpenSearch is a collection of technologies that allow the publishing of search results in a format suitable for syndication and aggregation. Introduced in 2005, it is a way for websites and search engines to publish search results in a standard and accessible format.
Media RSS (MRSS) is an RSS extension that adds several enhancements to RSS enclosures, and is used for syndicating multimedia files in RSS feeds. It was originally designed by Yahoo! and the Media RSS community in 2004, but in 2009 its development has been moved to the RSS Advisory Board. One example of enhancements is specification of thumbnails for each media enclosure, and the possibility to enclose multiple versions of the same content.
The Extensible Metadata Platform (XMP) is an ISO standard, originally created by Adobe Systems Inc., for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets.
In computing, a news aggregator, also termed a feed aggregator, content aggregator, feed reader, news reader, or simply an aggregator, is client software or a web application that aggregates digital content such as online newspapers, blogs, podcasts, and video blogs (vlogs) in one location for easy viewing. The updates distributed may include journal tables of contents, podcasts, videos, and news items.
FeedSync for Atom and RSS, previously Simple Sharing Extensions, are extensions to RSS and Atom feed formats designed to enable the bi-directional synchronization of information by using a variety of data sources. Initially developed by Ray Ozzie, Chief Software Architect at Microsoft, it is now maintained by Jack Ozzie, George Moromisato, Matt Augustine, Paresh Suthar and Steven Lees. Dave Winer, the designer of the UserLand Software RSS specification variants, has given input for the specifications.
The RSS-DEV Working Group was the outgrowth of a fork in RSS format development. The private, non-commercial working group began with a dozen members in three countries, and was chaired by Rael Dornfest, researcher and developer of the Meerkat RSS-reader software.
GeoRSS is a specification for encoding location as part of a Web feed. (Web feeds are used to describe feeds of content, such as news articles, Audio blogs, video blogs and text blog entries. These web feeds are rendered by programs such as aggregators and web browsers.) The name "GeoRSS" is derived from RSS, the most known Web feed and syndication format.
Web syndication technologies were preceded by metadata standards such as the Meta Content Framework (MCF) and the Resource Description Framework (RDF), as well as by 'push' specifications such as Channel Definition Format (CDF). Early web syndication standards included Information and Content Exchange (ICE) and RSS. More recent specifications include Atom and GData.
The Publishing Requirements for Industry Standard Metadata (PRISM) for the Internet, computing, and computer science, is a specification that defines a set of XML metadata vocabularies for syndicating, aggregating, post-processing and multi-purposing content.
↑ Powers 2003, p.10: "Another very common use of RDF/XML is in a version of RSS called RSS 1.0 or RDF/RSS. The meaning of the RSS abbreviation has changed over the years, but the basic premise behind it is to provide an XML-formatted feed consisting of an abstract of content and a link to a document containing the full content. When Netscape originally created the first implementation of an RSS specification, RSS stood for RDF Site Summary, and the plan was to use RDF/XML. When the company released, instead, a non-RDF XML version of the specification, RSS stood for Rich Site Summary. Recently, there has been increased activity with RSS, and two paths are emerging: one considers RSS to stand for Really Simple Syndication, a simple XML solution (promoted as RSS 2.0 by Dave Winer at Userland), and one returns RSS to its original roots of RDF Site Summary (RSS 1.0 by the RSS 1.0 Development group)."
↑ Winer, Dave (December 25, 2000). "RSS 0.92 Specification". UserLand Software. Archived from the original on January 31, 2011. Retrieved October 31, 2006.
↑ Winer, Dave (April 20, 2001). "RSS 0.93 Specification". UserLand Software. Archived from the original on November 2, 2006. Retrieved October 31, 2006.
↑ Festa, Paul (August 4, 2003). "Dispute exposes bitter power struggle behind Web logs". news.cnet.com. Archived from the original on August 6, 2009. Retrieved August 6, 2008. The conflict centers on something called Really Simple Syndication (RSS), a technology widely used to syndicate blogs and other Web content. The dispute pits Harvard Law School fellow Dave Winer, the blogging pioneer who is the key gatekeeper of RSS, against advocates of a different format.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
") icon was decided upon by several major web browsers. [6] RSS feed data is presented to users using software called a news aggregator and the passing of content is called web syndication. Users subscribe to feeds either by entering a feed's URI into the reader or by clicking on the browser's feed icon. The RSS reader checks the user's feeds regularly for new information and can automatically download it, if that function is enabled.
