The code’s on GitHub. And if you dig into the demo pages you can find the source code hidden inside the <div> element that contains the map itself. It looks pretty straightforward, a nice API. I’m a bit alarmed to see methods like “chloropleth” and “dotgrid” right on the map object; that suggests the author has in mind a set of hardcoded visualization types. I hope he’s left room for other developers to easily add their own visualization types. Also none of the examples have any navigation, none of the usual pan/zoom controls we expect. That’s totally fine for many visualizations, but may distinguish the uses of this library compared to Leaflet and friends.