The On Screen Display (OSD) used in Zenith's Cable TV set-top boxes utilize an Authoring System to allow development of control screens, data structures and state definitions. These, when combined with information provided from the RDBMS, define its display and behavior capabilities. This paper provides an overview of Zenith's ScreenPlay(TM) Authoring System used for the development of downloadable dialogs. Also discussed are the components of the Authoring System with respect to the modular, object-oriented design, and the advantages and limitations of the implementation.