Microsoft's mobile OS isn't Windows -- it's Cortana

We'll have bots to thank for that, and Microsoft wants developers to embrace them, the same way hordes of developers embraced iOS apps back in 2008. "We want every developer to build experts for Cortana," Nadella said onstage Wednesday. "We want all developers to build bots." Because of the cross-platform nature of both Cortana and the many communication apps Nadella cited yesterday, Microsoft's bot army will work on whatever device you want to use. The company debuted a host of tools yesterday to make that happen, including the Microsoft Bot Framework, which will let developers build bots and deploy them across the various communication platforms we use.