Abstract: This paper describes XLDE-an environment for developing application programs for array processors. It was written in Prolog. The main tools consist of instruction-level symbolic-digital-mixed simulator, executiable code generator. ??ing data base generator, editor, window-copier and so on.. Using a pop-up menu and symbolic simulation, XLDE has a friendly interface to the user. Prolog is a choice to rapid prototype and some Al features are introduced to the system. XLDE can be running on IBM PC/XT AT or their compatibles.