Implementing Design Patterns is gradually getting more common in the PHP world. The hype around Ruby on Rails, which is based on the Model-View-Controller architectural pattern, has spawned a generation of PHP based frameworks which embrace this pattern also, paving the way for others to embrace design patterns in general in their PHP applications.

Design patterns are just a standardized way of doing something (like a Factory where, when you request an object, if one already exists you get that one instead of a new one). They illustrate the design pattern concept with a database abstraction system (UML) and a configuration setup where the main class inherits from the child type-specific ones.