FeedTree
- http://www.feedtree.net/
- Collaborative RSS and Atom delivery using using peer-to-peer multicast. Includes information for readers and publishers.
FriendFeed
- http://friendfeed.com/
- Allows you to build a customised feed of made up of content your friends on other collaborative sites have shared, including news articles, photos, videos and comments left.
GeoRSS
- http://georss.org/
- Provides details of how to add geographic data to RSS and Atom feeds using Geography Markup Language (GML) or the simplified GeoRSS standards.
Yahoo Pipes
- http://pipes.yahoo.com/
- An interactive feed aggregator and manipulator. List of 'hot pipes' to subscribe to, and ability to create your own (yahoo account required).