Microsoft has long been a driver of alternate user interaction models on the PC; its first mouse shipped back in 1983, two years before Windows appeared and a year before the Apple Macintosh made the mouse mainstream. Then came the first pen- and stylus-driven operating systems, with pen support for Windows 3.1 in 1995. Windows XP and Tablet PC took that model a lot further, while touch support arrived in Windows Vista.
Now, with the current generation of Windows, those familiar computer interactions are joined by cameras (both the familiar 2D and newer depth-based devices), dials, voice, and even eye-tracking hardware.
