ArcGIS Explorer Desktop is a GIS viewer that gives you an easy way to explore.
ArcGIS Engine is a complete library of embeddable GIS components for developers.
ET GeoTools improves the editing capabilites of ArcGIS.
It is a set of tools for ArcGIS that enable the users to create surfaces.
It adds projections and geotransformations for use with ArcGIS Explorer Desktop.
