Powerful API that allows to query and retrieve changeset information. (Source Code)
Open-Awesome is built by the community, for the community. Submit a project, suggest an awesome list, or help improve the catalog on GitHub.
operational issues about the Postpass instance run on postpass.geofabrik.de
Read-only API that serves up custom selected parts of the OSM map data. (Source Code / Wiki)
SPARQL API for OSM data. (Wiki)
Free extracts of OSM features as GeoJSON, filtering on tags and bounding box. (Docs)