RSSOwl is a free, opensource RSS / RDF / Atom Newsreader.
Some special features are:

  - Export News to PDF, HTML, RTF, OPML
  - Import Favorites from OPML
  - Full text-search with syntax-highlight of the results
  - Powerful Newsfeed search-engine
  - View news in internal browser
  - Manage favorites in categories (Drag and Drop support)
  - Runs on Windows, Linux, Solaris and Mac

For a complete list of features, see: http://www.rssowl.org/overview

WWW: http://www.rssowl.org/