RSS 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 a "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.
Atom
Main article: Atom (standard)
In reaction to recognized issues with RSS (and because RSS 2.0 is frozen), a
third group began a new syndication specification, Atom, in June 2003. Their
work was later adopted by the Internet Engineering Task Force (IETF) leading to
the publication of a specification (RFC 4287) for the Atom Format in 2005. Work
on the Atom Publishing Protocol, a standards-based protocol for posting to
publishing tools is ongoing.
The relative benefits of Atom in comparison to the two RSS branches are a matter
of debate within the Web-syndication community. Supporters of Atom claim that it
improves on RSS by relying on standard XML features, by specifying a payload
container that can handle many different kinds of content unambiguously, and by
having a specification maintained by a recognized standards organization.
Critics claim that Atom unnecessarily introduces a third branch of syndication
specifications, further confusing the marketplace.
Atom aims to define both a syntax and a protocol for updating user blogs and
thus goes beyond the simple remit of RSS. While this is appealing to many users,
particularly those in the blogging community, it has been met with resistance in
the professional community (mainly publishers) due to its lack of
extensibility.[15]
For a comparison of Atom 1.0 to RSS 2.0 see Atom Compared to RSS 2.0.
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.
BitTorrent and RSS
The peer-to-peer application BitTorrent has also announced support for RSS. Such
feeds (also known as Torrent/RSS-es or Torrentcasts) will allow client
applications to download files automatically from the moment the rss reader
detects them (also known as Broadcatching). Most common BitTorrent clients
already offer RSS support.