If you're curious, it's called StageKeep, and you can find it here. https://stagekeep.com/
The original project used React Three Fiber, but refactored it to SVG for reasons I don't quite remember. I was inspired by signed distance functions, and the fact that one function could have such an outsized visual effect. Although the software doesn't use SDFs, but I like the idea of atomic functions that accepts some input, and outputs SVG.