PSX is a framework for developing dynamic Web sites in PHP. The goal of PSX is to help you develop RESTful APIs serving Web standard formats like JSON, XML, Atom, and RSS. It has a focus on social technologies and provides classes to use and implement OAuth, OpenID, Opengraph, Opensocial, Opensearch, PubSubHubbub, Atom, and RSS.
Sql2xml is a CGI program that lets you request a SQL query and convert it to JSON, CSV, XML or INI through a Web server. Sql2xml supports requests from multiple users and for multiple databases. It is intended for developers who do not have direct access to database servers due to firewalls or other restrictions.
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.