L systems are language-theoretic models for developmentalbiology. They wereintroduced in 1968 by Aristid Lindenmayer(1925-1989) and have proved to be among the most beautifulexamples of interdisciplinary science, where work in onearea induces fruitful ideas and results in other areas. Lsystemsare based on relational and set-theoretic concepts, which are more suitable for the discrete and combinatorialstructures of biology than mathematical models based oncalculus or statistics. L systems have stimulated new worknot only in the realistic simulation of developing organismsbut also in the theory of automata and formal languages, formal power series, computer graphics, and combinatorics ofwords. This book contains research papers by almost all leadingauthorities and by many of the most promising youngresearchers in the field. The 28 contributions are organizedin sections on basic L systems, computer graphics, graphgrammars and map L systems, biological aspects and models, and variations and generalizations of L systems. Theintroductory paper by Lindenmayer and J}rgensen was writtenfor a wide audience and is accessible to the non-specialistreader. The volume documents the state of the art in the theory of Lsystems and their applications. It will interest researchersand advanced students in theoretical computer science anddevelopmental biology as well as professionals in computergraphics.