GeoJSON is an open standard format designed for representing simple geographical features, along with their non-spatial attributes. It is based on JSON, the JavaScript Object Notation.

This plugins adds a new type of field into Advanced Custom Field. It displays an OpenStreetMap as input and output data as GeoJSON format.

If you want to know more about the GeoJSON format, here is the link to official reference, which is contains a link to the Working Group.

Feel free to contribute, this is an attempt to add a free, and open map to ACF.