A Lindenmayer system written in python 3
The controls are relatively straightforward. Left click to step forward an iteration and right click to step back an iteration. It will output the String it is drawing from in the console and doesn't draw immediately, but works like a turtle to look cooler. The default settings for the L-System is a sierpenski triangle, but it is relatively easy to change the rules and actions to accomodate any other 2D design.