The Geocodio Authentication PHP Sample Code demonstrates how to set the API Key to authenticate. Geocodio offers batch geocoding, partial address parsing, spelling correction, and address normalization.
This article is part of a 10-part series about interesting APIs that were added to our directory during 2016. Mapping and Location APIs are covered in this segment. The APIs were chosen by our researchers, by popularity according to website traffic, and by mentions on social media.
Take a look at MapCruncher. A very interesting new map mashup technique from the folks at Microsoft Research. It basically allows you to overlay any digital map image on top of a normal, zoomable Virtual Earth map.