The definitive resource for L-Systems, this University of Calgary site is maintained by Lindenmayers collaborators. It contains many articles, and a full-length copy of 'The Algorithmic Beauty of Plants'.

Overview of L-systems at Wolfram MathWorld. Includes supporting links and demonstration notebook.

Generative art tools that create complex 2D and 3D objects breeding LSystems, Cellular Automata, and Shape Grammars. Freeware by Umberto Roncoroni.

A simple implementation of Lindenmayer systems written in Python.

A mathematical introduction to how L-Systems work.

A well rounded introduction to L-Systems.

A basic introduction to L-Systems with some colourful examples.

A guide to the theory behind L-Systems.

Windows software and some information on LSystems and related ideas.

Modeling and visualization of plants using parametric L systems.