Geocoding

This is the one hard part about going open source geo.

Web services:

• Yonder - Compare geocoding results from multiple providers.
• GeoPy - Python library has a Yahoo and some opensource options.
• https://github.com/straup/js-geocoder
• https://github.com/straup/js-geolocation
• https://github.com/straup/js-reversegeocoder
• Edina Unlock - Excels with historic places but also uses modern UK data, and global modern places via GeoNames.org and Natural Earth.

Open source tools:

• OSM Nominatim - Used in OpenStreetMap, tied to OSM data.
• MapQuest's version of Nominatim - Warning, assumes USA addresses.
• GeoCommons GeoCoder - an open-source Geocoder using open data mostly just for the US using Census geography files
• Gisgraphy - an open-source Geocoder using open data

###Not a batch geocoder, but useful:

• http://aaronland.info/iamhere/ - Decimal degrees, DDMMSS, geohash, and WOE ID place reverse geocode.
• Geonames Reverse Geocoder services list