Lately I’ve been learning about RSS Syndication. Here’s a list of rss parsers. For Plone, here’s some info about cmffeed, how to add feeds within Plone howto, a chapter (PDF) from Ben Hammerly’s book on content syndication and RSS 2.0. What I really want to know: how to integrate and filter newsfeeds from various sources. Here’s also a list of newsfeed resources.
On another note, here’s a helpful reference comparing blogging software features.