A grab bag of practices and techniques for JavaScript development for the core language and some browser specific concerns. The Essentials, Literals and Constructors, Functions, Object Creation Patterns, and Code Reuse Patterns chapters mostly rehash material from "JavaScript: The Good Parts". The author provides additional exposition on the concepts but doesn't introduce much new material. The Design Patterns chapter includes some good examples of JavaScript implementations but accurately points out many already exist in third party libraries. The DOM and Browser Patterns chapter provides a brief introduction to browser specific concepts and concerns but you'll want to consult the referenced books for more detailed discussions. This book is a great primer for JavaScript development due to the breadth of topics is covers but is worth a pass if you've already read other JavaScript books covering these topics.