Theme frameworks also make theme development more accessible, removing the need for programming knowledge.
The Sandbox is a powerful tool available for WordPress theme designers and developers. The Sandbox can be easily designed just with CSS, so beginners will feel comfortable not bothering with PHP.Rich with powerful and dynamic semantic class selectors, Sandbox is a canvas for CSS artists.
Hybrid (Justin Tadlock)
Hybrid is a WordPress theme framework designed with content in mind. There is no other theme that will display your content in a meaningful way like this one does. It’s all about getting your information out there to the world. Without all the fuss. That’s what Hybrid does.
A highly extensible, search-engine optimized WordPress Theme Framework featuring 13 widget-ready areas, grid-based layout samples, styling for popular plugins and more.
The coding, functionality and support rivals the best in “premium” themes. With one, important, difference—Thematic is completely free and open source.
WP Framework is a powerful WordPress Theme Framework that aides WordPress Theme Authors to perform rapid theme prototyping. WP Framework handles all the essentials while you focus on your theme's specific features.
To learn more about how you can take advantage of this amazing Framework, visit the website for more information http://wpframework.com.