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
In October 2017, Microsoft officially launched Windows Mixed Reality and a lineup of third-party headsets for use with the Windows 10 "Fall Creators Update" (including a launch lineup of headsets from Acer, Dell, HP, and Lenovo, and future products from Asus and Samsung), officially referred to as Windows Mixed Reality immersive headsets. Unlike HoloLens, these devices are only compatible with virtual reality software, but the underlying ecosystem is referred to as Windows Mixed Reality regardless of experience. All Immersive headsets feature integrated motion tracking (eschewing standalone sensors), and contain cameras that can be used to track handheld motion controller accessories, which may be bundled with the headset, or distributed as optional accessories.