This is a screenshot of a free and open-source game <a rel="nofollow" class="external text" href="https://github.com/HackerPoet/MarbleMarcher">Marble Marcher</a>, taken by me. The game is licensed under the GPL. It is based on 3D fractals. Aliasing can be seen in the image.
HackerPoet and Marble Marcher contibutors
GPL
Screenshot