What is this tutorial about? The developerWorks tutorial series on design patterns began with the tutorial " Java design patterns 101 ," which explored the history and common structure of published design patterns for the Java language. As a general introduction, that tutorialfocused on some of the most well-known design patterns, those devised by theso-called Gang of Four. The Gang of Four (GOF) patterns apply to generalcomputing problems and can be implemented for a variety of applications andsystems. The GOF patterns are ubiquitous: in any modern, well-designed system,you will likely see one or more of these patterns implemented. Many people considerthemselves well-versed in object-oriented design patterns if they know the GOFpatterns. But design patterns extend far beyond the GOF. In this tutorial, you will find out just how much you don't know about design patterns.We'll start by exploring a number of resources that newcomers to the study of designpatterns often miss. These resources provide patterns that are invaluable to variousdomains of computing, such as business applications, Web applications, and evenWeb design. Next, we'll use design patterns found through some of these resources