Hexagon

Partial feature list:

• More preprocess hooks for manipulating template variables. Drupal 6 only provides one. Hexagon adds two more. pre_preprocess invoked before the default preprocess function and re_process which runs after.
• Granular separation of support files for better management of code. Template variable processors or "preprocess" functions can be grouped into files based on the module that originally implements the template. For example, variable processors for the template "user-profile.tpl.php" and "user-profile-category.tpl.php" can be placed in "user.common-vars.inc" ("user.theme.inc" in versions 1.5 and above for theme functions and variable processors.). It can also be very granular by naming them based on the template name itself, "user-profile-category.vars.inc".
• Plug-ins for commonly used functionality across multiple themes. This is where snippets specific to theming become obsolete. Once a plug-in is created, all you need to do is enable them in your theme's .info file. Common functionality can be shared and specific components can be overridden for individual themes.
• File caching and smart overrides for all types of files. Core already does this for template (.tpl.php) files. It's common to have a default implementation but to override it with a specific instance for a sub-theme. There are API functions to tap into this functionality. Since the files are cached, each theme based on Hexagon can refer to a file in a consistent way completely separate from any path hierarchies eliminating broken paths. All file paths will never break even if the project is restructured.
• Plenty of optional API functions to aid in development.
• Normalized CSS from core for a consistent look and smaller footprint.

A 1.5 beta release is available.

1.5 beta 2 is available.

1.5 beta 3 is available.

Notes on Drupal 7 development.

Hexagon was developed with the help of the Knight Foundation and Funny Monkey.