The OpenXR working group - previously known as the Khronos VR Initiative - is creating an open and royalty-free standard for VR and AR applications and devices.

The Problem:
Without a cross-platform standard, VR applications, games and engines must port to each vendors' APIs. In turn, this means that each VR device can only run the apps that have been ported to its SDK. The result is high development costs and confused customers - limiting market growth.

The Solution
The cross-platform VR standard eliminates industry fragmentation by enabling applications to be written once to run on any VR system, and to access VR devices integrated into those VR systems to be used by applications.OpenXR Architecture
OpenXR defines two levels of API interfaces that a VR platform's runtime can use to access the OpenXR ecosystem. Apps and engines use standardized interfaces to interrogate and drive devices. Devices can self-integrate to a standardized driver interface. Standardized hardware/software interfaces reduce fragmentation while leaving implementation details open to encourage industry innovation.Editor's Note:
So, summing it up, and taking a page from our previous article on the now defunct nomenclature of Khronos VR Initiative:

OpenXR aims to create a standard API that interfaces with all hardware APIs and takes the extra work out of the equation for developers. It looks like the implementation of a high-level API, in essence - a common programming interface that allows developers to basically "ignore" vendor and device-specifics, potentially trading higher performance for simplicity of programming. Instead of fully programming for three different platforms - such as SteamVR (OpenVR), Oculus (OVR), and OSVR - with an assortment of different game-engines and hardware specifications, developers will instead be able to use a single API that scales through all of those, with the bulk of the work being done by the API itself. This is an apparent step-back from where the industry is going, lower level and closer-to-the-metal, at least on usual graphics workloads - as Mantle, DX 12 and Vulkan attest. In reality, it might give the VR platform the glue that keeps it all a coherent whole. The number of partners on this project, for one, is astounding, including the heaviest names in the industry, such as Intel, AMD, NVIDIA, and ARM, just to mention a few. And this goes a long way to instill confidence on the standard as to de-facto becoming one.