Virtual reality
Around the same time, Douglas Engelbart used computer screens both as input and output devices. In 1968, Ivan Sutherland, with the help of many students including Bob Sproull, created what was widely considered to be the first head-mounted display (HMD) system for use in immersive simulation applications. It was primitive both in terms of user interface and realism, and the HMD to be worn by the user was so heavy that it had to be suspended from the ceiling. The graphics comprising the virtual environment were simple wire-frame model rooms. The formidable appearance of the device inspired its name, The Sword of Damocles.
Windows Mixed Reality
The premier device for Windows Mixed Reality, Microsoft HoloLens is a smart-glasses headset that is a cordless, self-contained Windows 10 computer. It uses various sensors, a high-definition stereoscopic 3D optical head-mounted display, and spatial sound to allow for augmented reality applications, with a natural user interface that the user interacts with through gaze, voice, and hand gestures. Codenamed "Project Baraboo", HoloLens had been in development for five years before its announcement in 2015, but was conceived earlier as the original pitch made in late 2007 for what would become the Kinect technology platform.