From OpenStreetMap Wiki
Search engine services
These options are available as services you can call
- Nominatim is deployed on OpenStreetMap servers, and powers the search on the front page as well as offering an API.
- LocationIQ.org runs nominatim with OSM data but on SSDs
- MapQuest also run nominatim with OSM data as part of their open initiative
- YaCy - a P2P open source search engine
- OpenCage hosted by Opencage Data Ltd - searches across OpenStreetMap, geonames, geoplanet among other sources.
- Photon hosted by Komoot.de
- GeoCheck hosted by IdeesLibres.org - searches across Nominatim OSM, Google, Photon OSM, ideeslibres.org BANO, IGN, Etalab BANO
- Osmocoder hosted by 123map.de, able to do batch geocoding, so far for area of Germany, and in German language.
Search engine software
These options can be deployed to your own server.
- OSMonto - a
- Pelias  is still in development by Mapzen ... uses elasticsearch, autocompletion and reverse geocoding (see blog entry how to set up an own instance)
- geopulse-geotag by factual.com
- OSM-Gazetteer by Dmitry Kiselev
- Oscar with a tiny description in