YourHead Software (http://www.yourhead.com) has announces Kiwi 2.0, an update to their customizable Twitter client for Mac OS X.

Kiwi 2.0 is now free, supports tabs and multiple windows, and provides quick and easy access to user profiles. The upgrade is also more customizable and has new themes. New rules allow users to filter, mark, or highlight desired content or tweets. Kiwi also supports picture posting, URL shortening, and @name completion, as well as many other Twitter specific features.

Kiwi 2.0 includes a whole new tabbed interface that gives users more control over their Twitter timelines. Users can view timelines in one window or break them out into separate windows. A new profile view gives detailed information about users and allows a user to follow, unfollow, and block other users as well as many other options.

Kiwi 2.0 comes with nine built-in themes, and dozens more are available online. Two new themes are available for users who prefer a more "minimal" look. Also, Kiwi is extensible with an application programming interface for building themes from HTML and CSS. Additionally, Kiwi 2.0 allows users to change the font size, merge timelines and edit the global hot keys.

Kiwi 2.0 requires Mac OS X 10.6 ("Snow Leopard") or higher. It's available in a free, ad-supported version or a $9.95 version with no ads. Site licenses and educational discounts are available from YourHead Software.