This is an expansion of the SteamVR preview program for Windows Mixed Reality headsets, which was previously open to developers but will open up to all users on November 15. Interested users will be able to navigate from Microsoft’s VR hub to Valve’s and select from SteamVR software there.
SteamVR is best known for games like EVE Valkyrie and Project Cars, but several apps are available too. For example, Virtual Desktop allows you to use your computer’s desktop in a VR space, and Google’s Tilt Brush is a VR painting experience. This preview program is a beta test, so not every app or game is expected to work perfectly right now.