BlogBridge is Free Open Source! It runs on Mac, Windows AND Linux.
BlogBridge the most powerful blog and feed reader. Are you an info-junky? Here's a high end aggregator that runs on any platform and is free to boot. You gotta check it out.
BlogBridgeManage your hundreds and hundreds of RSS subscriptions with an elegance and style, build rivers of news, perform complex queries -- all of this is and many more is delivered to your very fingertips.