amo is using it quite a lot, mainly for the scratch map feature in the Bump Map application, but not only.

Use cases are: - data storage - data aggregation/clustering - spatial indexing - geometrical computation (as long as you're OK with approximation, you can speed up a lot of things by working with CellID instead of actual geometries) - data visualization

I've seen it used by Databend, Helium, Breakroom (they did an Erlang binding on top of h3o), beaconDB, Greptime, Meilisearch. But I don't exactly know what they are using it for (just that they pulled h3o in their projects).

Hi. I am from GreptimeDB team. We use h3o library to implement h3 functions:

https://docs.greptime.com/reference/sql/functions/geo/#h3

These functions encode and decode latitude/longitude to H3 cells and provide utilities for querying cell properties, neighborhoods, distances, and relationships.