Able is a free theme for WordPress created by Automattic.
A multipurpose, traditional blog theme which contains up to a large three-column layout that is clean, responsive, and highly readable.
(Description "Able" Theme from wordpress.org)
You can download Able for free via the provided download link and include it into your themes folder of your WordPress installation. Also you can directly search for it in the WordPress admin interface in the themes section and install and activate it from there.
More information, screenshots and reviews of Able Theme can be found here.