XR has been trending for many years, and so far we've all seen awesome demos, like being on the moon, on a roller coaster, playing horror games and watching 360 videos. But while we're busy creating standards, we're forgetting the most important part of XR. Our brain. Now, I'm not saying that we shouldn't develop what we've been already developing. But, XR is, in fact, a technology. That's more than a content medium. XR has recently used for treatment for PTSD, ADD & ADHD, OCD, various phobias, and even for vaccinations. So, what else is XR being used for? And how do tools developed by Mozilla help? Let's find out!