A software tool for modeling and generating user windows of a graphical user interface of a software application has a modeling component for creating models of window types and instances thereof, a conversion component for converting model information into ASCII code, a library component for storing reusable code, and a window generation component for generating graphical user interfaces windows. The tool is characterized in that graphical user interface windows are generated in a batch process wherein certain fields shared by the windows are automatically populated with the appropriate application code taken from or inherited from the wintype model.