Today we have fully integrated support for RSS pinging in weblogs.com.
In 1999, when weblogs were still pretty new, but not so new that you could visit them all in an afternoon, it became useful to have a way to find out which blogs had updated recently. So I wrote a tool that would check the weblogs and when one updated, it would add it to a list of recently updated blogs.
Eventually there were so many blogs that we couldn't check them, we had to ask them to tell us when they updated, that's when the "pinging" started. Now the pinging process records not only the address of the weblog, but if it's provided, the address of the RSS feed for the weblog.
Popular services like Technorati, Feedster and Pubsub.com are built on the output of weblogs.com.
In December 2004, as an experiment, we implemented an "extended" ping handler that allows a caller to specify the address of an RSS feed in addition to the address of the weblog. This could make it easier for applications that use the output of weblogs.com to do interesting things with RSS. So far there's not been much adoption of the extended ping, but perhaps that will change now that the RSS url is included in a new version of changes.xml.
What's new in changes.xml
1. In the top-level weblogUpdates element, the version attribute changes from 1 to 2.
2. A weblog element may contain an optional rssUrl attribute containing the address of the feed if the ping was an extended ping.
3. These features also are present in shortChanges.xml.
If you're the developer of a weblog tool, you might adapt your tool to call the "extended" ping handler, since it provides more information to weblogs.com. If you're a user of a weblog tool, you might check with your vendor to see if your tool supports it, and if so, how you can activate it. If you have any questions, please post them here as a comment.