Apophysis is a piece of open source software that produces fractal images. It is free to download and use, with versions for Windows, Apple Mac, and Linux operating systems.

 

Many people use Apophysis to produce fractals that they then import into editing software such as Photoshop, or GIMP, to use as a layer or to add filters and distortions to produce very complex images. If you have not yet tried working with fractals, give this one a go.