This paper describes the use of Tcl and Tk to implement a ``soft" or generic GUI for real time control systems. UCO/Lick Observatory is using Tcl/Tk in conjunction with a relational database to implement a suite of code for instrument control and observing at Keck Observatory. One Tcl/Tk application serves as both the GUI builder and the GUI. It relies on information from an authoritative database to configure its behaviour. The project illustrates the use of Tcl and Tk as the common language holding a complex project together, and the particular suitability of Tcl to database applications. It also illustrates a software design philosophy in which an online database engine is an integral part of software design and deployment, rather than the target of the application.