AirSpace: Microsoft's secret weapon for cross-operating-system development. As mentioned above, Microsoft is expected to start referring to its cross-Windows framework as "Universal Windows Platform." But that doesn't mean the company has thrown in the towel on seeking ways to make it simpler for developers to write for all operating systems, including Windows.
The Office team at Microsoft has managed to build Office apps in a way that allows the Microsoft dev team to reuse a lot of core C++ Office code across Android, iOS and Windows. There's something called "AirSpace" that Microsoft has developed that enables the company to get the rest of the way. From what little Microsoft has shared publicly about AirSpace, this technology could include a set of practices, plus possible APIs and tooling for building apps that can run across multiple operating systems. Build might be where Microsoft takes the wraps off AirSpace and talks about its own lessons learned.