Web applications have become the major means to allow ubiquitous access to backend systems via a web browser. Several technologies such as JSP, ASP.NET, or Java Server Faces exist today that help in developing web applications. These technologies do not support the migration of existing legacy desktop applications written with a GUI class library such as Swing, Qt, or GTK to web applications. The framework presented in this paper allows the programmer to expose arbitrary desktop applications as web applications without requiring any changes in the source code of that application. Dialogs are rendered using HTML and JavaScript and a flexible event model transparently forwards user interaction at a web browser to the application running at the backend. By employing a cross-language compiler it is also possible to transparently execute parts of the application on the client side inside the web browser. 1 Motivation Web browsers are generic clients that allow access to arbitrary services. ...