The Qt toolkit is widely used for the development of GUI applications as well as console tools and servers. Qt is most notably used in KDE, a free Linux desktop, the Opera web browser, Skype, and Google Earth. Daniel Molkentin, author of this book, is a core developer of KDE. He uses practical examples to explain Qt characteristics like the signal slot concept and its event system. He guides the reader through developing applications both with and without Qt's graphical GUI builder "Qt Designer." Topics covered include: tools needed to create dialog boxes; steps to follow when developing a GUI-based application; layout; how to visualize data using Qt's "model-view concept"; the QtSql model; the graphics library; as well as how to work with XML, databases, threads, and debugging. The book also includes lots of useful hints on how to use Qt's own datatypes, containers and algorithms and how to develop user-friendly applications. Co- published with Open Source Press.