Understanding the working of X11 from the ground up (2017)
This was a really nice demo! It can even be used to understand concepts used in the HTML5 canvas, such as aliasing. Hell, it could possibly used as en entry to learning how to program ray tracers. At the bare bones, construction of complex bodies in POV-Ray was used by Constructive Solid Geometry hearkening back to the basic union, xor, intersection, etc, operations done in the demo, at least on a conceptual level.