1. A method for controlling simultaneous execution of one or more computer application programs in one or more host computer systems under control of a second computer system which may be remote from the one or more host computer systems, where said computer application programs may be dissimilar to each other, and said host computer systems may be dissimilar to each other, said host computer systems generating presentation information based on said application programs or on generic computer messages, or both, said method employing a programming framework for building customized gateways for said application programs; said method comprising the steps of: establishing a plurality of relevant selected parameters in said host computer presentation information; said relevant selected parameters having a variable time of occurrence and context in said presentation information; interpreting selected portions of said host computer systems' presentation information in said application program being executed; and executing one or more of said application programs under the control of said second computer system through a customized gateway on the basis of said interpreted presentation information, said gateway utilizing an external object database to provide information for customizing said gateway.