OpenStreetMap-data from: 2020-05-04
Site is still in its early development stage.
OSM-Boundaries aren't open source itself, but it uses software that is. Here is a list of such software.
BSD 2-Clause "Simplified" License
Creative Commons Attribution-ShareAlike 2.0
Map-tiles and source data for boundaries.
Font Awesome Free License
Free license (with attribution)
Various icons made by Roundicons from www.flaticon.com
Created as a substitute for the great https://wambachers-osm.website/boundaries/ since it was shut down early 2020.
Copyright © 2020 Ground Zero Communications AB. All Rights Reserved.