Cysphere is an integrated social networking server for smaller virtual communities. It provides a private mailbox, public and private discussion forums, and simple file sharing, and makes it as simple as possible for users to communicate over the Web in a secure way. It includes an embedded Web server and SQL database and requires no installation or maintenance.
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.