Some Evernote Atlas insights from MapBox, which created the underlying geocoding service
“The geocoder is powered by 100% public domain data. We are using Natural Earth for countries and provinces, Flickr Shapefiles for cities, and U.S. Census TIGER for zip codes. We combined these sources into a database of nearly 200,000 places that the MapBox geocoder uses to quickly return accurate results.
In addition to the existing data, we are working with others in the OpenStreetMap community to establish guidelines that ensure the ODbl does not virally infect users’ data when using OpenStreetMap for geocoding. Once finalized we can add OpenStreetMap point and polygon data to the geocoder and work with the larger community to improve the entire system.”