In addition to WMS services, and ArcGIS Server services, GeoGATE also can consume OpenStreetMap (OSM), as the following example shows.
In Map Services dialog, select OSM from the drop-down list, and OSM will appear on map view, click “Add Map Service to Add it on Map”.
OSM will be added to map, as shown below; sometimes, you need to zoom to view OSM, if your initial extent is at low scale.
On map side, OSM will be loaded as shown below.