Vienna

Vienna is an open source Mac OSX RSS reader with support for RSS/Atom/JSON feeds, article storage and management via a SQLite database, written in Objective-C and Cocoa.

Feeds can be accessed directly, or through a syncing service supporting the Open Reader API, like BazQux.com, FreshRss.org, FeedHQ.org, InoReader.com or TheOldReader.com.

Development now happens on GitHub: https://github.com/ViennaRSS/vienna-rss