A simple class hierarchy to implement turtle graphics in Java, intended to be use as an educational example of inheritance and polymorphism in a course of object oriented programming in Java. Different subclasses of Turtle respond to their commands in different styles such as rendering their path as dotted lines or subdivided fractal shapes, each responding to the same method calls defined in the abstract superclass Turtle. Also includes a class LSystem that can used to subdivide fractal paths for these turtles to render.

All computer science instructors can use and adapt these classes for their needs as they see fit. The source code of these classes is released under GNU GPL v3 licence.