It's custom. I explored a Redis fork months ago, prior to the ability for modules. https://github.com/tidwall/redis-gis https://github.com/tidwall/redis-gis I

It's custom. I explored a Redis fork months ago, prior to the ability for modules. https://github.com/tidwall/redis-gis https://github.com/tidwall/redis-gis I then tried to make a module but redis modules do not support hooking into the pubsub tooling, so Tile38 live geofencing and webhooks were not possible.