ArcGIS Explorer is a free, downloadable GIS Viewer that gives you an easy way to explore, visualize, and share GIS information. ArcGIS Explorer adds value to any GIS because it helps you deliver your authoritative data to a broad audience.
With ArcGIS Explorer, you can
Access ready-to-use ArcGIS Online basemaps and layers.
Fuse your local data with map services to create custom maps.
Add photos, reports, videos, and other information to your maps.
Perform spatial analysis (e.g., visibility, modeling, proximity search).