FlexNet Publisher license management software must be installed to manage ArcGIS Desktop Concurrent Use, ArcGIS Engine Concurrent Use, ArcInfo Workstation, ArcGIS CityEngine, and ArcGIS Pro concurrent use software. Information about the version of Flexnet Publisher used in each version of ArcGIS License Manager can be found in the Technical Article titled FAQ: What version of FLEXnet Publisher is used in ArcGIS License Manager? In an enterprise environment, ArcGIS License Manager can also host and distribute enterprise single use licenses or ArcGIS Pro and Premium App named user licenses through ArcGIS Enterprise portal.