This book is a step-by-step guide with ready-to-run codes to guide you in developing applications with GNOME. If you have programming skill either in Linux or other operating systems and want to have GNOME 3 as one of your deployment targets, then this book is for you. This book is also for commercial software developers or an open source software hacker. The reader needs to be familiar with Vala and JavaScript before starting to develop Gtk+ and Clutter applications.