It's D3 according to the source file; the type of map is called a 'choropleth'. Here is a tutorial that might be useful. (I haven't done this specific one but

It's D3 according to the source file; the type of map is called a 'choropleth'. Here is a tutorial that might be useful. (I haven't done this specific one but I've made similar stuff before.) http://www.cartographicperspectives.org/index.php/journal/article/view/cp78-sack-et-al/1359 http://www.cartographicperspectives.org/index.php/journal/ar...