[caption id="attachment_17598" align="aligncenter" width="618"] Chances are pretty good that Windows Phone's Cortana won't look like this.[/caption] Microsoft’s long-rumored Cortana digital assistant will make its debut with Windows Phone 8.1, according to a software development kit leak. Anonymous sources speaking to The Verge detailed Cortana’s attributes, which will include “a Notebook feature that will allow Windows Phone users to control exactly what information is shared with the digital assistant.” Cortana will draw data from Bing, Foursquare, and other services to answer users’ spoken questions; on the visual side of things, the app will appear as a colored icon that will animate and “bounce around.” Cortana’s behavior will reportedly mimic that of Apple’s Siri or Google Now, scheduling appointments and answering queries about the weather or the user’s daily schedule. (The name “Cortana” is a hat-tip to the digital assistant in the Halo games, who often appears as a blue lady.) It remains an open question whether Microsoft will port this app to its other products, including the Xbox One (which already boasts some degree of voice-driven control) and Windows. But Cortana is also a late arrival into the digital-assistant arena. Apple launched Siri in October 2011; Google Now first appeared on Android smartphones in 2012 before expanding to iOS in 2013. Moreover, Google and Apple effectively split the mobile-device market in a duopoly. If Microsoft wants Cortana to draw more users to Windows Phone, which is struggling to seize significant market-share from its larger rivals, feature parity simply isn’t enough—the assistant needs to include some sort of “must have” feature that truly sets it apart. Cortana (and by extension, Siri and Google Now) could also face competition from a mix of tech giants and brash young startups. In 2013, for example, Facebook acquired Mobile Technologies, which builds speech-recognition and machine-translation software; if the social network is willing to leverage its users’ information in the same way as Google does with Google Now (which can access Gmail and other branded services in order to draw info about appointments, contacts, and more), it could field a powerful assistant. So that’s another element of uncertainty facing Microsoft, even as it finds itself the underdog to the two biggest companies in the space. No pressure.   Image: Microsoft