Rail Yard is a next-generation PHP framework. It brings together common patterns like MVC and ActiveRecord, follows convention over configuration, is built on PHP 5 and follows PHP best practices.
Why another framework? CakePHP, CodeIgniter and Zend are all very good but I believe they miss a few key points. First, routing inside an application doesn't just rely on URL — sessions, cookies, AJAX and APIs all play a part. Rail Yard uses a dispatcher class for routing requests. Second, the lack of a decent ORM: although most assume an ORM maps only to a database, it could also map to a service. Rail Yard follows Rails' ActiveRecord and ActiveResource. Third, how frameworks map actions to views: in Rail Yard your actions interact with a layout object that gets rendered against a layout view, with content filled by rendering views into sections — combining views in an object-oriented fashion.
There are more modern PHP frameworks that handle these cases now. Still an interesting exercise in MVC framework design.
NOTE: This project is archived but you can still find the source code.