Headquartered in Redmond, Washington, USA, its most profitable products are the Microsoft Windows operating system and the Microsoft Office suite of productivity software. As of the third quarter of 2009, Microsoft was ranked as the third largest company in the world, following PetroChina and ExxonMobil. It is also one of the largest technological corporations in the world. Microsoft possesses footholds in other markets than just IT software, with assets such as the MSNBC cable television network and the MSN Internet portal. The company also markets both computer hardware products such as the Microsoft mouse and the Microsoft Natural keyboard, as well as home entertainment products such as the Xbox, Xbox 360, Zune and MSN TV.