Vienna is a newly announced news-reader for OS X. From the product page, it looks to have many of the same features as NetNewsWire or Newsfire, but Vienna is different in that it is totally free. Vienna is available for download as either a pre-compiled version, or the raw source code. This seems to be the first open-source project that compares to the big commercial programs. I will be posting a review of this software some time within the next week, as soon as I get a good feel for it.