Relational growth grammars (RGG) area graph rewriting formalism which extends the notations and semantics of Lindenmayer systems and which allows the specification of dynamical processes on dynamical structures, parti cular ly in biological and chemical applications. RGG were embedded in the language XL, combining rule-based and conventional object-oriented con structions. Key features of RGG and of the software GroIMP (Growth grammar related Interactive Modelling Platform) are listed. Five simple examples are shown which demonstrate the essential ideas and possibilities of RGG: signal propagation in a network, cellular automata, globally-sensitive growth of a plant, a “chemical” prime number generator, and a polymerisation model using a simple mass-spring kinetics.