You can download GeoFrameworks software, documentation, free spatial data, device driver updates and mobile device SDK's from the GeoFrameworks Download Center.

NationalAtlas.gov is a web site offering several map layers available for North America and the United States, from basic political boundaries to census information and biological information. All of the data on this web site is public domain and may be used in your applications. Data is provided as ESRI(R) shapefiles and GeoTIFF imagery.

TIGER is a free online resource of geospatial data for the United States. Detailed information is available for streets, railroads, counties, states, cities, and other various boundary information. TIGER data files are public domain.