1. A software tool for modeling and generating user windows of a graphical user interface of a software application comprising: 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; 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.