Creating / displaying POIs programmatically

It would be beneficial if we could access and create Points Of Interest
dynamically through Javascript in an aircraft gauge. I can think of plenty of
ideas where such a feature would come in very useful, allowing some creative
and immersive uses, that wouldn’t really fit the static nature of a mission. I
have a suspicion that such a system already exists, and if so, having it
documented for use would be wonderful. At a minimum, we would need to be able
to assign a latitude/longitude and a name. Further settings, such as the type
of graphic displayed to the user, along with the ability to dynamically turn
on and off these developer-created points of interest, would also be useful.