Managed by the U.S. Geological Survey's (USGS) National Geospatial Program, The National Map has transitioned data assets and viewer applications to a new visualization and product and service delivery environment, which includes an improved viewing platform, base map data and overlay services, and an integrated data download service.
This new viewing solution expands upon the National Geospatial Intelligence Agency (NGA) Palanterra X3 viewer, providing a solid technology foundation for navigation and basic Web mapping functionality. Building upon the NGA viewer allows The National Map to focus on improving data services, functions, and data download capabilities. Initially released to the public at the 125th anniversary of mapping in the USGS on December 3, 2009, the viewer and services are now the primary distribution point for The National Map data.
The National Map Viewer: http://viewer.nationalmap.gov
Additional publication details
USGS Numbered Series
The National Map: New Viewer, Services, and Data Download