Cisco Systems, Inc. (known as Cisco) is an American multinational technology conglomerate headquartered in San Jose, California, in the center of Silicon Valley, that develops, manufactures, and sells networking hardware, telecommunications equipment, and other high-technology services and products. Cisco is the largest networking company in the world. The stock was added to the Dow Jones Industrial Average on June 8, 2009, and is also included in the S&P 500 Index, the Russell 1000 Index, NASDAQ-100 Index and the Russell 1000 Growth Stock Index.