Abstract: A client/server data processing system is developed by a method (20) in which a meta model (21) is transformed by a model generator (24) into an application model (25) which has a layered structure reflecting that of the end-product system. A code generator is associated with each layer of the application model (25). For the client side, an IDL representation (41) is generated and is transformed into client interfaces (46). Client user interfaces (47) are separately generated.