RSS is a special XML format used to publish frequently updated content, such as blog posts, news items or podcasts. Users don’t need to check their favorite web site for updates. Rather, they can subscribe to a URL and be notified about changes automatically. This is can be done using a dedicated tool called feed reader or aggregator, but most web browsers integrate this capability as part of their core functionality. If a web site offers an RSS feed, this is depicted with an icon like the one in below.
The RSS XML format is very much like XHTML, but much simpler. As standardised in the RSS 2.0 Specification, RSS essentially is composed of two parts, the channel and the news item specifications. While the channel describes some general properties of the news feed, the items contain the actual stories that change over time. Below we see an example of such a feed. In Figure 134 we see how the same feed is presented within a feed reader.
<?xml version="1.0" encoding="utf-8"?> <rss version="2.0"> <channel> <title>Seaside ToDo</title> <link>http://localhost:8080/todo</link> <description>There are always things left to do.</description> <item> <title>Smalltalk</title> <description>(done) 5 March 2008</description> </item> <item> <title>Seaside</title> <description>5 September 2008</description> </item> <item> <title>Scriptaculous</title> <description>7 September 2008</description> </item> </channel> </rss>