One of the two roots are selected by random and then after a number of pre-iterations (10-20) the position of is constantly plotted after each iteration. The method is very much like the "random game" IFS method.
All fractals are from self-written tools - linear IFS images from my: "2D IFS Studio", non-linear (rev Julia) from "3D RJIFS", (that also writes 2D rev Julias), escape time Z² fractals from "Julia dream", the rest are from small "hacks".