Over the past few years, augmented reality software / applications have become more complex but also easier to write. From iOS 11, the developer was able to build with Apple's ARKit framework. Facebook also introduced Camera Effects in April, Google has ARCore for Android.
WebXR can be an important step forward for AR, enabling the creation of an augmented reality experience right on the browser, then moving from desktop to mobile. It also helps to reduce barriers to participation in this world. Just need to know JavaScript and have Firefox to create an AR application.
Mozilla is not the only company trying to bridge the gap between web, WebVR and augmented reality. Google recently launched an extension for WebVR WebARonARCore https://github.com/google-ar/WebARonARCore running on Android as a separate APK.
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Firefox started supporting virtual reality
What is AR? What is VR? Are these two technologies similar and different?