3.1 RSS 0.91

The oldest and most established RSS standard still in use, RSS 0.91 was originally released by Netscape's RSS team, led by Dan Libby, in July 1999. It was later refined and further documented by Netscape, with Userland Software's Dave Winer. It is based on a combination of Netscape's RSS 0.90 and Userland's own older ScriptingNews 2.0b1 format. Neither of those formats are used in any meaningful way today, but RSS 0.91 continues. At the time of this writing, Syndic8 ? one of the largest RSS aggregators on the web ? has 55% of its feeds declaring themselves as RSS 0.91. While later versions of the 0.9x standard build on this original spec in many useful ways, 0.91 is a good place for the RSS practitioner to start. Figure 3-1 shows a tree representation of RSS 0.91.

Figure 3-1. A tree representation of RSS 0.91

3.1.1 The Specification in Summary

  • XML-based.

  • Consists of one channel, containing up to 15 items.

  • Each item has a title, a description, and a URL.

  • Limited metadata, only applying to the channel.

  • Pull-based: the user must request the feed.

  • Feeds can contain an optional text entry box.

Example 3-1 is an example of RSS 0.91.

Example 3-1. An example of RSS 0.91
<?xml version="1.0" encoding="ISO-8859-1" ?>
<rss version="0.91">
  <title>RSS0.91 Example</title> 
  <description>This is an example RSS0.91 feed</description> 
  <copyright>Copyright 2002, Oreilly and Associates.</copyright> 
  <pubDate>03 Apr 02 1500 GMT</pubDate>
  <lastBuildDate>03 Apr 02 1500 GMT</lastBuildDate>
    <title>RSS0.91 Example</title> 
    <description>Computer Books, Conferences, Online Publishing</description>
    <title>The First Item</title> 
    <description>This is the first item.</description> 
    <title>The Second Item</title> 
    <description>This is the second item.</description> 
    <title>The Third Item</title> 
    <description>This is the third item.</description>