- Leaflet: https://leafletjs.com/
Plain and Simple.
Good solution if you want a simple map with a few markers and/or GeoJSON data. - OpenLayers: https://openlayers.org/
Swiss knife.
Good solution if you want a map more complex features (WMS, WFS, ...). - MapLibre: https://maplibre.org/
Open-source fork of Mapbox library.
You need a map, you need a database with (geographical) data from all over the World, don't go any further, OpenStreetMap is the solution.
- Main website: https://www.openstreetmap.org/
- Wiki: https://wiki.openstreetmap.org/
- API: https://overpass-api.de/ (playground: https://overpass-turbo.eu/)
If you need help, contact Belgian community via https://openstreetmap.be/en/contact.html
There are also most likely members of the Belgian community that are part of osoc, ask around.
The following services are based on OpenStreetMap data.
- openrouteservice:
https://openrouteservice.org/ - GraphHopper:
https://www.graphhopper.com/ - Open Source Routing Machine (OSRM):
http://project-osrm.org/ - ...
- Geoportal of the Belgian federal institutions:
https://www.geo.be/ - Geopunt (Flanders - Vlaanderen):
https://www.geopunt.be/catalogus - Géoportail de la Wallonie (Wallonia - Wallonie):
https://geoportail.wallonie.be/catalogue-donnees-et-services - bric.brussels (Brussels - Bruxelles - Brussel):
https://bric.brussels/en/our-solutions/urbis-solutions - ...