FYI, if you are concerned about RSS security, you will be happy to know that Aggie RC5 strips all script, object and meta tags from text before displaying it. I have constructed an opml file I use for testing. The opml file contains links to five RSS feeds that test security, and other RSS parsing problems. The individual RSS feeds can also be loaded directly from this directory, where the feeds that test security are named securityN.xml. Feel free to use these resources to test your aggregator of choice.

Special thanks to Ingve Vormestrand for originally pointing out these flaws with Aggie and working up the test feeds.