What are L-systems?
L-systems, or Lindenmayer systems, were not invented to create fractals but to model cellular growth and interactions. A L-system is a formal grammar to transform, by iteration, a starting string of characters into another string. The transformation is based on rules that specify how characters or sub strings are substituted by others. By recursively applying the rules of the L-system to an initial string, a string with fractal structure can be created. Basically, each character can be a symbol having any conventional meaning, depending on what you intend to model. Very soon, L-systems have been applied to draw complex figures, each character being interpreted as a graphic command. The conventions used can be freely chosen in each program implementing L-system. The following example is quoted from the Fractint manual (by courtesy of Tim Wegner) and, therefore, use the particular syntax of this program. It draws the well known Dragon curve which illustrates the first page of each chapte
