RSS stands for “Really Simple Syndication”, while Atom is an XML language used for web feeds. Confused or want to know more? You can read the Web 2.0 blog for further information about RSS, Atom and Web 2.o in general; or Network with other Web 2.0 users on the social network for development and Peace; or simply read the overview we publish below. Wiki docet

BLOG RSS: Rss 

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 USAGE

Web feeds are used by the weblog community to share the latest entries’ headlines or their full text, and even attached multimedia files. (See podcasting, vodcasting, broadcasting, screencasting, Vloging, and MP3 blogs.) These providers allow other websites to incorporate the weblog’s “syndicated” headline or headline-and-short-summary feeds under various usage agreements. Atom and other web syndication formats are now used for many purposes, including journalism, marketing, bug-reports, or any other activity involving periodic updates or publications. Atom also provides a standardized way to export an entire blog, or parts of it, for backup or for importing into other blogging systems. A program known as a feed reader or aggregator can check webpages on behalf of a user and display any updated articles that it finds. It is common to find web feeds on major Web sites, as well as many smaller ones. Some websites let people choose between RSS or Atom formatted web feeds; others offer only RSS or only Atom. In particular, many blog and wiki sites offer their web feeds in the Atom format.

Client-side readers and aggregators may be designed as standalone programs or as extensions to existing programs like web browsers. Browsers are moving toward integrated feed reader functions, such as Safari RSS, Web Browser for S60, Opera, Firefox and Internet Explorer. Such programs are available 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) web feeds into new feeds, e.g., taking all football related items from several sports feeds and providing a new football feed. There are also search engines for content published via web feeds, including Technorati and Blogdigger.

Atom Compared to RSS 2.0 

One difference between the two is that RSS 2.0 may contain either plain text or escaped HTML as a payload, with no way to indicate which of the two is provided, while Atom uses an explicitly labeled (i.e. typed) “entry” (payload) container. It allows for a wider variety of payload types including plain text, escaped HTML, XHTML, XML, Base64-encoded binary, and references to external content such as documents, video and audio streams, and so forth. Other differences include:
- RSS 2.0 has a “description” element which can contain either a full entry or just a description. Atom has separate “summary” and “content” elements. Atom thus allows the inclusion of non-textual content that can be described by the summary.
- Atom is defined within an XML namespace whereas RSS 2.0 is not.
- Atom specifies use of the XML’s built-in xml:base for relative URIs. RSS 2.0 does not have a means of differentiating between relative and non-relative URIs.
- Atom uses XML’s built-in xml:lang attribute as opposed to RSS 2.0’s use of its own “language” element.
- In Atom, it is mandatory that each entry have a globally unique ID, which is important for reliable updating of entries.
- Atom 1.0 allows standalone Atom Entry documents whereas with RSS 2.0 only full feed documents are supported.
- Atom specifies that dates be in the format described in RFC 3339 (which is a subset of ISO 8601). The date format in RSS 2.0 was underspecified and has led to many different formats being used.
- Atom 1.0 has IANA-registered MIME-type. RSS 2.0 feeds are often sent as application/rss+xml, although it is not a registered MIME-type.
- Atom 1.0 includes an XML schema. RSS 2.0 does not.
- Atom is an open and evolvable standard developed through the IETF standardization process. RSS 2.0 is not standardized by any standards body. Furthermore according to its copyright it may not be modified.
- Atom 1.0 elements can be used as extensions to other XML vocabularies, including RSS 2.0 as illustrated in a weblog post by Tim Bray entitled “Atomic RSS”.
- Atom 1.0 describes how feeds and entries may be digitally signed using the XML Digital Signature specification such that entries can be copied across multiple Feed Documents without breaking the signature.
- Despite the emergence of Atom as an IETF Proposed Standard and the decision by major companies such as Google to embrace Atom, use of the older and more widely known RSS 1.0 and RSS 2.0 formats has continued.
- RSS 2.0 support for enclosures led directly to the development of podcasting. While many podcasting applications, such as iTunes, support the use of Atom 1.0, RSS 2.0 remains the preferred format [5].
- Many sites choose to publish their feeds in only a single format. For example CNN, the New York Times, and the BBC offer their web feeds only in RSS 2.0 format.
- News articles about web syndication feeds have increasingly used the term “RSS” to refer generically to any of the several variants of the RSS format such as RSS 2.0 and RSS 1.0 as well as the Atom format. (For example, “Fine-Tuning Your Filter for Online Information” (NYT) and “There’s a Popular New Code for Deals: RSS” (NYT January 29, 2006))
- Each of the various web syndication feed formats has attracted large groups of supporters who remain satisfied by the specification and capabilities of their respective formats.
- Atom supports multiple link elements per entry, a feature which can be used to specify enclosures of different types. This eliminates the need for separate feeds for podcasts that provide multiple file formats.