Looks like it's made using BlueShift. There's a link in the lower righthand corner of the graphic. https://blueshift.io https://blueshift.io Both the BlueShift

Looks like it's made using BlueShift. There's a link in the lower righthand corner of the graphic. https://blueshift.io https://blueshift.io Both the BlueShift examples and the graphic on this page are loading d3 as well, so it's likely BlueShift is building on d3 in some way.