The Senate Address Geo-coding Engine (SAGE) is a web service used to provide geo-mapping information to users.  It includes address verification/correction, geo-coding of addresses, and district assignment using either Board of Election street files or TIGER/Line shapefiles.  Most of SAGE's functionality is handled by third-party libraries and services, such as the USPS Address Information System, as well as geocoders from Yahoo, Google, MapQuest, and Bing.