https://github.com/KiranWells/corgi
Like a lot of graphics programmers, I fell into the rabbit hole of rendering fractals. However, I never stopped - over the past couple of years I have slowly been building one of the most sophisticated Mandelbrot/Julia rendering programs that I am aware of. It has a mostly intuitive user interface, and does all of the calculations on the GPU. It has to use a bunch of mathematical tricks to get around the limits of single-point precision available in shaders. Because of the GPU rendering algorithm, I’ve managed to view fractal locations at around 10^250 times magnification with near real-time performance.
I also built a really in-depth compositing/coloring system, allowing you to make some really crazy images and get a lot of variation even for the same location:
Although it has only been me working on it, I think it is in a pretty mature state so far, and I would gladly take PRs/issues if anyone happens to be interested. It should support any OS if you compile it from source, but I don’t have binary releases set up yet.
I personally enjoy playing around with fractals - I’ve built several fractal rendering programs (this is the latest), and they are quite fun to play around with. While they are more art from math than art from code, there are a lot of creative things you can do in code to visualize different features of fractals - Inigo Quiles has great examples of this, as well as non-fractal procedural art such as SDFs.