lsys studio v0.1. Freeware. Copyright © 2008 Jari Komppa

CommandFunction
.Move forward
*Draw a star in current position
+Increase current variable
-Decrease current variable
(Push position and rotation in stack
)Pop position and rotation from stack
XSelect variable X (rotation around X axis)
YSelect variable Y (rotation around Y axis)
ZSelect variable Z (rotation around Z axis)

See http://iki.fi/sol/lsys.html for more detailed explanation.