MapQ is an easy to use wrapper for the Mapquest Geocoding API. It advises developers to interact with the API by making the environment variable in the local environment. Developers can also interact with the Geo class to work with the API.
Google has just announced the addition of a valuable new feature for the Google Maps API (the most popular API in our API directory): reverse geocoding. If you are not familiar with geocoding, it is the process of converting an address into a latitude/longitude pair. Likewise, reverse geocoding is the process of converting a latitude/longitude pair into an address. Developers using the Google Maps API have had access to geocoding since its release in June 2006, and geocoding has been integrated with many of the map mashups developed with this API.
The Google Maps API is listed as the most popular API in the ProgrammableWeb API directory. Because of its ease of use, plus the infinite possibilities for hacking together mashups, has made it the most popular API by far, way beyond the Twitter API and Youtube API.