This presentation introduces the Qooxdoo JavaScript framework. Qooxdoo allows building rich desktop-style applications that run in a web browser. The presentation covers the architecture of Qooxdoo applications, the available widgets and layout managers, and demonstrates how to create a simple temperature converter application using test-driven development principles in Qooxdoo. Hands-on exercises guide attendees in using the Qooxdoo tooling and developing a basic user interface.