Sapphire is an object-oriented PHP5 web framework designed to let you focus on your data and business logic.

Everything you make in Sapphire can be broken down into modules. This includes all the code, templates, and even configuration files.With extensions (aka mix-ins), you can make modules that modify the behaviour of other, more core, modules. The end result: a framework that is perfect for creating modular, reusable code.

Source: Sapphire