Advances in hardware, system software, and browsers have created consumer-grade platforms to display 3D and VR at price points that the nearly affordable world-wide. X3D needs to step up to meet these capabilities and provide the right service to developers and consumers. The following is a list of written or planned posts on the topic of X3Dng listed in order of best reading. Articles and links will be updated as they become available.
Documentation and examples for ThreeJS.org are complete. There are a lot of contributors who are always adding material. In the world of simple-VR, there is the StereoEffects for rendering. This is an effects that renders the scene into left/right eye split-screen.
For the last nine months I have been working on a declarative language for VR/AR/MR to display 3D content in a browser. I have called the language XSeen.