PROGRES (PROgrammed Graph REwriting Systems) [1] has been developed since the late 1980s, and thus constitutes one of the eldest implemented graph rewriting languages and environments. It is based on the logicoriented approach to graph grammars. The PROGRES language allows to model the structure and the behavior of software applications in a visual and declarative way. Thereby, it is not tied to a specific application domain, but may be used for arbitrary software applications (see [2] for a simple example). Besides an extensive language, PROGRES offers an integrated modeling environment, including a syntax-directed editor, an interpreter, and a debugger. Furthermore, the environment supports rapid prototyping by generating executable source code from a specification. The code can be embedded into a visual prototype.