(Gahh) Mapping API / Service?

A few weeks ago, I found a new[ish] cloud-based mapping API service offering rich visual customization of the map displays (much more so than Google), and the ability to create custom (fictional) maps, in addition to real-world coverage maps.

Anybody here know the name of this service?

And yes. I’ve Googled. :expressionless:

…

Thanks very much! :smiley: