The tech world is torn apart in two sides of the present day debate- the utility of Virtual Reality and Augmented Reality. However, what joins both sides in consensus is that the development and deployment of the AR and VR should be easier- especially on the web. Mozilla, in a similar direction, is developing a combined framework for developers to access standardized, well-documented tools for user’s chosen mixed reality platform.
The construction of such a platform will allow developers to build things on the web, the deployment of which is not just limited to desktop browsers, but to mobile, VR and AR headsets, and anything else that is capable of doing a little reality mixing. The strategy is simple, if these things are going to be a part of our world, might as well make them easier to deploy.
At present, it's simply an open playground for developers to innovate- the platform supports desktop Firefox and there’s a WebXR Viewer on the iOS App Store. To know more about the project, you can check out GitHub.