11/2/2010 -- RSS stands for Really Simple Syndication. RSS is a format for syndicating -- gathering and making available -- the content of Web sites, primarily news-oriented sites and blogs. RSS can be used to provide any kind of information that can be broken down into discrete items and put into RSS format. Such RSS-formatted content is an RSS feed, and an RSS-aware program can check the feed periodically for changes, download new items and make them available to the user. The RSS format is a dialect of XML (eXtensible Markup Language). All RSS files conform to XML 1.0 specification.

Many versions of RSS are available, but three versions -- 0.91, 1.0, and 2.0 -- are in widespread use. Netscape designed RSS version 0.90 for gathering and displaying headlines from news sites. A simpler version, 0.91, was proposed, and UserLand Software picked up that version for use in its blogging product. At the same time, another noncommercial group had evolved RSS 0.90 into RSS 1.0, which is based on resource description format, or RDF (see www.w3.org/rdf). UserLand didn't accept RSS 1.0 but instead continued evolving RSS 0.91 through versions 0.92, 0.93 and 0.94 and finally settled on RSS 2.0 (skipping 1.0 because that version number was already taken). Currently, many blogs and Web sites use RSS 0.91 for basic syndication (title, URL and description), RSS 1.0 for readers that use RDF, and RSS 2.0 for advanced syndication with more metadata. (Think of metadata as data about data, which is what the RSS format provides: It provides data about other information, such as blogs and news.) RSS 1.0 files have a .rdf extension, whereas RSS 0.91 and 2.0 files have a .xml extension. However, all RSS files are text files that use XML tags.

Examining an RSS Feed
An RSS feed is a text file with XML tags that describe a Web site's content. You typically use an automated program to periodically generate the RSS feed file, but you can prepare the RSS feed file using a text editor. It's good to know what an RSS feed looks like, just so you can debug problems with the feed.

The specific details of an RSS feed depend on the version of RSS. The simplest feed is RSS 0.91, and here's a typical RSS 0.91 feed:

<?xml version=”1.0”  ?>

  <!-- A comment line --->

  <rss  version=”0.91”>

  <channel> <!--- This tag specifies  general information about the feed--->

  <title>Title of this  feed</title>

  <link>URL of this feed, for example,  http://edulaney.typepad.com/</link>

  <description>Brief description of feed</description>

  <language>en-us</language>

  <item>

  <title>Title of this  item</title>

  <link>URL for this  item</link>

  <description>Description of this  item</description>

  </item>

  ... more items ...

  </channel>

  </rss>

Reading RSS Feeds
Many GUI programs are available for subscribing to RSS feeds and reading items from a feed. These programs are RSS aggregators because they can gather information from many RSS feeds and make everything available in a single place.

The two types of RSS aggregators are Web browser plug-ins and standalone programs. Browser plug-ins, such as NewsMonster, run in a Web browser so that the feeds appear in the Web browser. Standalone programs such as GNOME Straw and KDE Akregator are complete GUI applications and usually look similar to other mail and newsreader programs.

Fedora and SUSE come equipped with the Akregator program, a standalone RSS feed aggregator. To run it, look for a link in the GUI desktop's applications menu (choose Application, then Internet and Akregator). If you don't see Akregator listed, type akregator in a terminal window. In Debian, you can install Akregator by typing apt-get install akregator (after typing su - to become root).

When Akregator first runs, it displays its main window without any RSS feeds. To subscribe to a feed, choose Feed, then Add Feed from the menu or right-click All Feeds in the left pane of the window and select Add Feed from the pop-up menu. Then type the URL for the feed in the Add Feed dialog box and click OK. For example, to read Slashdot's RSS feed, type http://slashdot.org/index.rss. The feed's title appears in the left pane of the window. Click the feed title to view the items in this feed. Then you can click an item in the upper-right pane, and that item appears in the lower-right pane. You can add many different RSS feeds, organize them into folders and browse them in Akregator.