We present the Genetic L-System Programming (GLP) paradigm for evolutionary creation and development of parallel rewrite systems (Lsystems, Lindenmayer-systems) which provide a commonly used formalism to describe developmental processes of natural organisms. The L-system paradigm will be extended for the purpose of describing time- and context-dependent formation of formal data structures representing rewrite rules or computer programs (expressions). With GLP two methods gleaned from nature are combined: simulated evolution and simulated structure formation. A prototypical GLP system implementation is described. Controlled evolution of complex structures is exemplified by the development of tree structures generated by the movement of a 3D-turtle. 1 L-Systems The development of an organism may [...] be considered as the execution of a `developmental program' present in the fertilized egg. The cellularity of higher organisms and their common DNA components force us to consider deve...