Major employers and economic generators include the Department of National Defence, the Port of Halifax, Irving Shipbuilding, the Nova Scotia Health Authority, IMP Group, Bell Aliant, Emera, the Bedford Institute of Oceanography, government, banks, and universities. The municipality has a growing concentration of manufacturing industries and is becoming a major multi-modal transportation hub through growth at the port, the Halifax Stanfield International Airport, and improving rail and highway connections. Halifax is one of Canada's top four container ports in terms of the volume of cargo handled. A real estate boom in recent years has led to numerous new property developments, including the gentrification of some former working-class areas.