A theme framework is a theme that is designed to be a flexible foundation that can serve as a parent theme for building child themes. The use of WordPress theme frameworks may ease theme development by reducing the volume of work which may be needed in creating a backbone for your theme (usually by using PHP and WordPress Template Tags).
Thematic is a free, open-source, highly extensible, search-engine optimized WordPress Theme Framework. Its power is based upon its flexibility and its simple customisation, you would be very hard pushed to find a project you couldn’t use the Thematic WP Framework for.
WP Framework was created to serve as the starting point in WordPress theme development, It accomplishes this by providing you with commonly used functions and features that modern WordPress themes should have. So when you start a brand new WordPress project, using WP Framework you’ll already have the basic functionality set so you don’t have to worry about mundane task like creating the loop, or recreating all the standard template files.
Vanilla’s key boast is this: Exceptional power and freedom for designers, without (or barely) needing to know or touch PHP. Thanks to the combined capabilities of PHPTAL templates, Carrington’s atomic templates, YUI CSS and full widgetization (including custom widget controls).
When designing WordPress themes, a large amount of time is spent writing the same code over and over again. I found it annoying. Granted, I know there are themes out there like Elliot Jay Stocks’ Starkers Theme (which I used), but none of them were quite to my style. Whiteboard is the result.
The Buffet Framework is a theme framework designed not only for the theme developers who will be using the theme actions and filters to create the child themes, but also for the end users who would be able to add and remove what they want.
Basis has been built to make theme development for WordPress easier. If you are an experienced theme developer or a total beginner, Basis provides a highly customizable starting point for your theme development.
Ashford was developed by Tim Bednar to aid organizations in customizing, building and growing simple web sites. It is a theme framework that many kinds of web site owners will find valuable: web workers, small business, bloggers, authors, new media, magazines, churches and nonprofits.