XML Feeds have been adopted by news services, weblogs, and other online information services to send content to subscribers. After subscribing to an XML feed, you will be notified when new content is available without having to visit the web site.
How to Subscribe
You will need to download and install a Feed Reader, or use a web-based service like Google Reader. Then, you copy and paste the URL of the feed (e.g. http://earthquake.usgs.gov/earthquakes/catalogs/1day-M2.5.xml) into the viewer’s “subscribe” dialogue. Example Feed Readers include:
Mozilla Firefox Web Browser (Windows, Mac, Unix)
Firefox has a feature called Live Bookmarks that lets you subscribe to an XML feed within the browser.
Google Reader is a free, web-based service for reading and managing Atom and RSS feeds online or offline.