[amitp]

I agree, Voronoi diagrams are so much fun! For that map project, at the last minute I switched to something slightly different. The page still says "Voronoi" but the actual demo doesn't use Voronoi. The Voronoi diagram uses the circumcenters of the triangles produced from Delaunay triangulation. I found that for my needs, the centroids worked better ("barycentric dual mesh"). Some comparison pictures here: https://www.redblobgames.com/x/1721-voronoi-alternative/ The graph connectivity is the same but the shapes are rounder.

I've not implemented Fortune's myself. I use the Delaunator library, which maintains all the additional information I wanted in the form of a half-edge triangle mesh: https://github.com/mapbox/delaunator ; Mike Bostock wrote a Voronoi wrapper on top it: https://beta.observablehq.com/@mbostock/the-delaunays-dual