http://plagger.org/trac
Plagger is like pipes for news feeds. You can read feeds from almost anywhere and output them to almost anywhere. It's written in perl.
http://gregarius.net/
Gregarius is a web-based RSS/RDF/ATOM feed aggregator, designed to run on your web server, allowing you to access your news sources from wherever you want.
http://feedblendr.com/
Does what it says on the tin, blends feeds. Give it a bunch of feed urls and it'll whip up together into one rich, dark, feed smoothie!
