There are a couple of ways to generate RSS type feeds (atom, rss 1.0, rss 2.0) from within roundup, either template based or detector based. These feeds are useful for letting tools like news readers track updates to a tracker. They can also be used to trigger other tools.
DetectorBasedFeedGeneration involves hooking in a detector to changes in issues and allowing the detector to generate a static file which can be subscribed to by news readers.
TemplateBasedFeedGeneration uses the standard roundup templating system to create feeds based on the incoming request. This is completely dynamic and more flexible.