Impletend with the graphic library Prologo.
The main source file is \Fractal-Vargas-Jose.pl, at the end of this file you can find the code of a library called ProLOGO that implements turtle grafics for prolog.
You can find screenshots of the fractals in:
\fractales-no-originales-Vargas-Josenon-original\fractales-originales-Vargas-Joseoriginally designed fractals
Example fractals:

