L-System 4

A program which uses text based instructions (seed files) to build complex 3D objects.
http://www.geocities.com/tperz/L4Home.htm

A Lindenmayer-systems Implementation

Macintosh software for download with documentation by Bryan Horling.
http://shakti.trincoll.edu/~bhorling/lsystems/

lsystem

A simple implementation of Lindenmayer systems written in Python.
http://www.alcyone.com/software/lsystem/

A Sketchbook on L-systems

Modeling and visualization of plants using parametric L systems.
http://coco.ccu.uniovi.es/malva/sketchbook/

Laurens Lapre's Lparser

Windows software and some information on LSystems and related ideas.
http://home.wanadoo.nl/laurens.lapre/

Mathematical Figures

Illustrations of 2D and 3D L-Systems created with Mathematica.
http://mathforum.org/advanced/robertd/index.html

LGrammar

A graphics tool for Lindenmayer systems in C and Java.
http://robotics.ee.uwa.edu.au/lgrammar/

L-Systems Tutorial

A mathematical introduction to how L-Systems work.
http://www.complexity.org.au/vlab/tutorials/l_systems/

An Introduction to Lindenmayer Systems

A basic introduction to L-Systems with some colourful examples.
http://www.biologie.uni-hamburg.de/b-online/e28_3/lsys.html

Algorithmic Botany

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

BioSchematics

An L-System interpreter and drawing tool for linux.
http://pagesperso.laposte.net/bioschematics/

Christian Jacob

A collection of papers related to using Mathematica to generate L-Systems.
http://pages.cpsc.ucalgary.ca/~jacob/Publications/Publications.html

New ALife Database

A collection of automatically collected L-System links.
http://www.aridolan.com/ad/adb/LS.html

LMUSe

Interprets L-Systems as MIDI music.
http://www.geocities.com/Athens/Academy/8764/lmuse/lmuse.html

Virtual Plants

A project involving Java3D and L-Systems.
http://www.hta-bi.bfh.ch/~swc/DemoJ3D/VirtualPlants/

Recursive Productions and Grammars

A guide to the rules of strict grammars including L-Systems.
http://www.cs.rit.edu/~afb/20013/plc/slides/grammars.html

Microbes, L-systems and music

Music generation using L-Systems, and how this relates to microbe growth.
http://ironbark.bendigo.latrobe.edu.au/~soddell/lsys/

L-systems

A guide to the theory behind L-Systems.
http://www.math.okstate.edu/mathdept/dynamics/lecnotes/node12.html#SECTION00040000000000000000

L-Systems Explorer

A Windows-based L-System program.
http://www.generation5.org/content/2002/lse.asp

Wikipedia L-systems

A well rounded introduction to L-Systems.
http://en.wikipedia.org/wiki/Lindenmayer_system