This is a Packt beginner's guide. The unique style of the book is to set the requirements for an application, Team Twitter, in the first chapter and apply the concepts in the application as you learn in the following chapters. When you complete this book, you would have developed a complete application. Although the scope of this book is only on the Qooxdoo framework, which is a client side framework, we have explained how to set up one of the RPC servers and demonstrated the end to end application in the Team Twitter. This book is intended for the client side developers who design and develop internet web applications and enterprise web applications. If you want to start developing RIA applications in Qooxdoo, this book would be a great help to jump start your development. If you are already developing Qooxdoo applications, this book will help you to go through the Qooxdoo framework quickly to improve your contribution to your project. This book is also intended for the desktop application developers who want to move into RIA development and develop internet web applications and rich enterprise web applications. It also provides an idea for the Architects and Lead developers to know about Qooxdoo and evaluate the framework. It helps beginners in Qooxdoo to easily set up the development environment and explains the concepts in an order that is easily graspable by beginners.