Hi, As I understand it, WebVR support has been in the last few Firefox Nightly builds, including the Mac version. I have an htc vive, with SteamVR Mac running (OS 10.13), and I see the VR button on videos from the Mozilla project/demo page, but nothing appears in the headset when I click them. Using Firefox 58.0a1 (2017-09-26) (64-bit)