These pages are a brief overview of each of the patterns in P of EAA. They aren't intended to stand alone, but merely as a quick aide-memoire for those familiar with them, and a handy link if you want to refer to one online. In the future I may add some post-publication comments into the material here, but we'll see how that works out. Many of these diagrams demonstrate the rather poor GIF output of Visio. The nice diagrams were redrawn for me by David Heinemeier Hansson