Not quite the same but reminds me a lot of the Commanche JS demake called VoxelSpace: https://github.com/s-macke/VoxelSpace

This needs a [2019] in the title (it's cool, but hasn't been touched in years)

Someone slap a Minecraft chunk file parser on the front of this and make an alternative to Overviewer (which I love but it is slow even on small worlds.)

Looks cool!