Windows 10 was Microsoft's most important product launch of the year. It shored up the desktop platform, it introduced a new approach to delivering and updating the operating system, and it created the opportunity for Windows to be everywhere.
But as important as it was, Windows 10 was not Microsoft's most interesting 2015 product. The most interesting products were the HoloLens augmented reality headset and the Surface Book hybrid laptop. OK, HoloLens isn't out quite yet—$3,000 developer units will be available in the first quarter of 2016—but it was first demonstrated back in January, upstaging Windows 10's consumer preview, which was shown off at the same time.
What was striking about both of these is that their reception was less about what they were and more about what they represented. HoloLens is obviously the grander ambition—a new kind of human-computer interaction depending on the melding of virtual 3D objects with the real world, driven by voice and gestures as well as the more conventional mouse and keyboard.