Abstract: An application Platform as a Service system includes a rapid development platform adapted to receive input and create a data-driven application. The rapid development platform provides a graphical user interface and at least one template for use in creating the data driven application. The system further includes a unified platform for executing the data-driven application, the unified platform coupled to the rapid development platform to receive and initialize the data-driven application. The unified platform is capable of communicating with and modifying a plurality of data sources responsive to the data-driven application, and providing a unified environment for executing the data-driven application. The system also includes a multi-system interface module having inputs and outputs for coupling the unified platform to the plurality of data sources. The present invention also includes methods for operation of the application platform as a service.