Cortana personal assistant spearheads new Windows Phone features

Players of the video game Halo will be familiar with Cortana, an artificial intelligence character. Now it's arriving on Microsoft's Windows Phone smartphone as a virtual assistant to take on Apple's Siri and Google Now. The move is one of a number unveiled by Microsoft at its annual Build conference in San Francisco on Wednesday as it seeks to gain traction in a highly competitive and lucrative market for smartphones. The most dramatic for handset makers - though not initially users - is that Microsoft will make both Windows Phone and Windows licences free for use on devices with screens smaller than 9in diagonally. That has been seen as an acknowledgement that the huge success of Google's free Android mobile OS, which dominates worldwide smartphone sales, has made it impossible for Microsoft to charge for software on those devices.