Online users in world
It shows users on the map with green and friends with yellow. This implementation will be good. 

FOSS gamedev and creative worlds
https://forums.minetest.org/

dadix wrote:I mean to transform Minetest I an application server which can be accessed through a variety of clients, on multiple protocols.
dadix wrote:The server side will be light with no unnecessary code.
rubenwardy wrote:There is a player radar mod somewhere.
Topywo wrote:https://forum.minetest.net/viewtopic.php?f=11&t=4835