RSS: Spreading the News

There is so much of it on the Web; the sheer volume makes it hard to keep up. Perhaps you have three favorite Web pages for international news, others for local, maybe five or ten for technical updates, a couple for business or stock quotes, and still others you check for entertainment. Who has time keep track of them all?

How would you like to have your own single customized Web page that combines the headlines from all your favorite sources? Netscape thought you might, and provided just that. Go to My Netscape at http://my.netscape.com to set yours up. On the flip side, suppose you were a news producer, would you want your headlines to be available to Netscape's users? That would be easy, too. The magic tool that makes this possible is an XML tag set called RSS, Rich Site Summary.

There are other RSS services, too. For example, My.Userland.Com, at http://my.userland.com (for general news; Userland codeveloped the RSS standard with Netscape), and Meerkat, at http://www.oreillynet.com/meerkat (for news with a technical bent). To get an idea of how versatile RSS can be, check them all out. These three sites all use RSS under the covers, but they definitely all have a different look-and-feel.

(Don't like how these sites look? RSS is simple enough that you don't need to use any of them as an intermediary. You can roll your own if you want.)

The gist of RSS is quite simple. Consider, for example, My Netscape. Each site that wants Netscape to promote its news makes an RSS file. Let's consider the ACCC, for example. If we wanted to make the news items on the ACCC home page available to users of my.netscape.com, we'd start with an RSS file, something like the file in figure 4. The RSS file begins with a small description of the overall site and has a title, description, and link for each news item. That's pretty much all there is to it.

<?xml version="1.0"?>

<rss version="0.91">

<channel> 
   <title>ACCC at UIC</title>
   <link>http://www.uic.edu/depts/ACCC/</link>
   <language>en-us</language> 
   <description>The ACCC Web site</description>

</channel>

<image>
   <title>ACCC</title>
   <url>http://www.uic.edu/logos/ACCC.gif</url>
   <link>http://www.uic.edu/</link>
   <width>88</width>
   <height>31</height>
   <description>News about the ACCC and more ...
   </description>

</image>

<item>
   <title>Email filters</title>
   <link>http://www.uic.edu/depts/accc/index.html/news.current.html#0</link>
   <description>There's a new Web email tool on the Mailtools Page, one that
    automates the creation of filters for incoming email.
   </description>

</item>

<item>
   <title>Mail Relays and Unregistered Machines</title>
   <link>http://www.uic.edu/depts/accc/index.html/news.current.html#1</link>
   <description>When we turned off open mail relays in the ACCC SMTP servers,
   people with on-campus machines that were not registered in the campus DNS 
   server were unable to send mail.
   </description>

</item>

</rss>

After we made the RSS file in figure 4 available on the Web, we'd register its URL with Netscape or Userland or Oreillynet. After that, Netscape or Userland or Oreillynet would pick up our RSS file periodically and display it (with links back to our site) to the users who ask for it.

Syndicated news, simple, yet powerful. Netscape, Userland, and Oreillynet let the user choose which RSS files they want to view, although I suppose they didn't have to. The key point is that sites can cooperate by sharing data in a standard XML format.

Bob Goldstein, bobg@uic.edu
ACCC Operating System Support and Development