It's a pretty large dataset for d3 to be loading, so it can take quite a while. It also seems to struggle on firefox. I have alot to learn about web app optimizations and building for multiple browsers and devices. And generally anything frontend :p.

Try waiting quite a while before interacting with it. An example topic "data science" should initialize the map data eventually.

In my case, Mac El Cap, FireFox will briefly load a topic and immediate reset the page. Safari appears as a giant no-op.