A design tool for hierarchical systems

Describes an approach for the development of hierarchical systems called ddraw (d esign draw). It is an object-oriented graphical design tool that allows the construction of structures by the use of a small set of graphical elements. A system in ddraw consists of components and relations between them. Components in turn may contain one or more subcomponents. Each of them can be provided with textual and graphical attributes. The attachment of any semantical meaning to components makes possible to employ ddraw in wide application fields. The created structures can be stored in an application-independent model description language (MDL), which allows its further use as input to other tools like code generators, syntax checkers, simulators, etc. Ddraw has been implemented on top of the X Windows system and uses windowing techniques and pointing devices to make the construction of complex systems manageable