What is Microsoft Cortana? Cortana is currently the code name for a whole new way of controlling Windows Phone, and in the longer term maybe Windows too. It will respond to your voice, answer your questions, control your device and anticipate the information you need at particular times. Is Cortana a real product, or just vapourware? It's a real product. Steve Ballmer mentioned reinventing the core shell of our family of devices to be deeply personalized, based on the advanced, almost magical, intelligence in our cloud that learns more and more over time about people and the world in his enormous staff memo this summer. We're in uncharted territory: Neither the desktop nor the social graph describes this new experience, and neither does the search box, the pin board or the file system, Ballmer says. The shell will support the experiences layer and broker information among our services to bring them together on our devices in ways that will enable richer and deeper app experiences... Our shell will natively support all of our essential services, and will be great at responding seamlessly to what people ask for, and even anticipating what they need before they ask for it. That means the ambitions for Cortana go beyond what Google, Facebook and Siri currently provide.