Qt 4 is radically different from earlier versions of Qt, with lots of new features and many small changes everywhere in the API. For customers porting applications from Qt 3 to Qt 4, this is bad news; but for us, this is good news, because it means that owners of the Qt 3 book will want to buy this one as well. Those who buy this book will: [1] Learn how to program Qt the right way, i.e. with the grain of the tool. [2] Learn standard patterns of Qt programming, from basic tasks like creating a file menu with a recently used files list to more complex tasks such as presenting data to the user through the user interface, and providing the user with the ability to interact with their data. [3] Learn how to extend Qt to meet their needs, for example, through subclassing and by composition. [4] Gain insight into programming in general and into graphical user interface programming in particular.