PHP On Pie is a PHP framework that combines the best ideas from PHP projects like Drupal, CodeIgniter, Kohana, and ZendFramework. It has very few core concepts: classes, models, events, slots, and tools. It lets you repackage completed apps into plugins that you or others can use later. Its smart database classes allow you to implement vertical and horizontal partitioning (sharding) easily to handle millions of users.
ACR is a Web CMS library that can be embedded inside any Turbogears 2 application to add CMS functions. It provides all the fundamental tools to allow an individual or a community to easily publish and manage a Web site with different content types, from Twitter streams to video galleries. It also provides an easy-to-use set of APIs to create new content types by defining your Views. ACR also comes with ACR_cms, a CMS implemented by using libACR.