This is a small book about how to write software patterns. The software development community has learned from Christopher Alexander's A Pattern Language that Patterns are a good way to capture the experience of expertise in a way that can be transferred to those who need that knowledge.
Software Patterns now covers patterns of software construction, but also organizational structure, Agile Software Development methods and other things. Most expertise can be captured in the form of patterns.
Patterns show how an expert approaches and solves problems found in their context. There is an active international community writing patterns of all kinds. This book gives advice on how to approach the writing and improvement of such patterns.
This book is about writing patterns, but does not contain patterns, other than a number of examples to show the process and the various forms.
The author has written over one hundred patterns and collaborated on many others. He has two pattern books in print.