Fractals are entities which are made up of smaller examples of themselves. They can be used to produce realistic looking objects.
In some examples each line in a fractal's 'initiator' is replaced by each line in the 'generator'. Thus more lines are produced, each of which is replaced by the generator ... The initiator and generator are also shown. You control how many times the lines are replaced.
The Pythagoras tree (both regular and irregular) is also given: Each branch has two branches added. The version made of squares is also there.
The famous Barnsley Fern is shown : many dots are plotted each calculated from the previous dot's place.
Also shown are Sierpinski space filling curves - made up of four mutually recursive shapes called A, B, C and D. Shape A for instance is A, \, B, _, D, /, A.