A window server used in real-time applications should be able to assure previously agreed-upon redrawing rates for a subset of windows while providing best-effort services to the remaining windows and operations such as moving windows. A window server used in embedded systems should be small and require only minimal operating system support, for example just threads and address spaces as provided by microkernels.In this paper, we present the design and an implementation of the DOpE window server. The key techniques used are to move redrawing responsibility from client applications to the window server and to devise a simple scheduling discipline for the redrawing subtasks.