Introduced at the Mobile World Congress in Barcelona in early 2010, Windows Phone 7 strays away from the previous Windows Phone platforms, and instead is built with inspiration from the OS found on Microsoft's Zune HD portable media player.
The "Metro UI" takes a minimalist approach by using "Tiles" to display phone options and apps as opposed to the traditional app menus seen on other platforms. These Tiles can display live updates and information from the homescreen.
Xbox Live integration was also introduced with Windows Phone 7, tieing in the Xbox 360 service to their mobile device, including gaming capabilities.
