A slim modular model-view-controller (MVC) framework written in PHP5.2+ for rapid development of web- or console-applications featuring an integrated db-api, template-logic, pretty-urls, internationalization, caching, data-models and a multi-layered file-tree.

They've just released version 20071127 adding all sorts of new features and bugfixes. Right now, there's not a whole lot to go on - several bits of documentation are listed to the right of the site, but the only real page is the introduction. If you'd like to be kept up to date on the project, though, you can always subscribe to their news feed.