Abstract: An applications server is operable to provide a plurality of user driven services by running an application program. The application program is arranged to provide the services in response to user commands for selecting service options. The applications server comprises in accordance with the application program a state machine able to determine a current state of the application program from one of a pre-determined set of states defining a logical procedure through the user selected service options. The states of the state machine includes for each of the modular services, one or more states associated with one or more forms within the service. Each form defines a state of a user interface for providing the services to the user, and each state includes one or more sub-states called situations, defining the commands to be recognised and the predicates to be satisfied to select that state depending upon the estimated user commands and the session state of the user session.