Abstract: A multi-module application has a main module that generates a homepage user interface in a window for accessing a number of function modules of the application. Upon startup of the application, the main module parses a startup xml file that stores information about the function modules and generates the homepage user interface. When a user selects a function provided by a function module, the main module runs the function module and switches from the homepage user interface to a user interface of the function module in the same window. The user may return to the homepage from the function module by selecting a homepage button in the user interface of the function module. When a function module is added or removed from the application, an installer or uninstaller program updates the startup xml file by adding or removing information about the function module.