FOSS gamedev and creative worlds

I have two ideas:
1. Is it possible to create a mod that displays the distance from other players?
2. Is it possible to create a mod with that you can mark the places and displays distance from this places? These points are only visible to the player who created them. (to prevent spam)
For example using commands:

/setpoint [point_name]
/removepoint [point_name]

My vision:

cactuz_pl wrote:I have two ideas:
1. Is it possible to create a mod that displays the distance from other players?
2. Is it possible to create a mod with that you can mark the places and displays distance from this places? These points are only visible to the player who created them. (to prevent spam)
For example using commands:

/setpoint [point_name]
/removepoint [point_name]

My vision:

This would require C++ of course; I'm pretty sure it is possible. It would be great, yes. :D
tip: 1 block = 1 cubic meter

Nice idea bro

Try to use my Radar. Maybe he can do what you need.