Spatial index with search methods such as NEARBY, WITHIN, and INTERSECTS.
Realtime geofencing through persistent sockets or webhooks.
Object types of lat/lon, bbox, Geohash, GeoJSON, QuadKey, and XYZ tile.
Support for lots of Clients Libraries written in many different langauges.
Variety of client protocols, including http (curl), websockets, telnet,
    and the Redis RESP.
Server responses are RESP or JSON.
Full command line interface.
Leader / follower replication.
In-memory database that persists on disk.