Mike Bostock is kicking off his next world changer with Observable HQ. I had just been lamenting recently that I really enjoyed Jypyter Notebooks, but found that it added a bit of friction before you could share your work out with the world. Observable looks it attacks the friction and makes it ridiculously easy to just play and publish.
Check out the live earthquake visualization that you can create in under 5 mins by watching this video.
Here is my version that includes a generator to make the earth spin. Much fun … will be messing with this more.