Nominatim is a tool to search OpenStreetMap (OSM) data by name and address (geocoding) and to generate synthetic addresses of OSM points (reverse geocoding). It can be found at nominatim.openstreetmap.org.
Nominatim is also used as one of the sources for the search box on the OpenStreetMap home page. Several companies provide hosted instances of Nominatim that can be queried via their APIs.
Nominatim was developed by the Open Street Map Foundation.
The data provided is licensed under the Open Data Commons Open Database License.
The documentation provided, including the cartography, are licensed under the Creative Commons Attribution-ShareAlike 2.0.