Vienna is a freeware, open source RSS/Atom news reader for the Mac OS X operating system. It comes loaded with a number of features that make it easy to use but still powerful.
Pros: Vienna is one of the most powerful news readers available for Mac OS X. Its simple and uncluttered user interface presents information in a very “Mac-like” fashion, and its “Smart Folders” feature allows users to easily organize articles via user-specified criteria.
Cons: None significant.
Note: For a good cross-platform news reader, try RSSOwl.