ArcGIS Engine is a complete library of embeddable GIS components for developers.
ET GeoTools improves the editing capabilites of ArcGIS.
ArcGIS extension with geospatial analysis capabilities for mlitary applications.
It expands the geodatabase functionality of the ArcGIS Explorer Desktop app.
GTP for ArcGIS the functionalities of ArcGIS to more than 90 raster formats.