Vienna 是一个 Mac OS X 操作系统下的 RSS/Atom 的阅读器，提供了很多商业阅读器才具备的功能，但又是开源的。
主要特点:
Subscribe to Atom/RSS news feeds and podcasts.
Simple and intuitive user interface with customisable toolbar.
Built-in tabbed browser.
Global search of all retrieved articles.
Automatic detection of newsfeeds on web pages.
Smart folders for organising related feed articles.
Custom article display styles.
Three separate reading layouts.
Blogging integration.
Support for downloading enclosures in articles
Filter the displayed articles.
Manual reordering of the subscription list.
Full AppleScript support.
Localised into several languages.
