# A Survey of the Real-Time Metaverse: Challenges and Opportunities +
## 7 Interoperability Standards
### WebXR  
WebXR is a robust application programming interface (API) that brings VR and AR experiences to the web, enabling developers to create immersive content accessible directly through web browsers [235]. WebXR is a standardized framework for integrating VR and AR capabilities into web applications, run by the World Wide Web Consortium (W3C). This eliminates the need for users to download specialized software or applications, allowing them to experience immersive environments simply by navigating to a webpage. As WebXR takes advantage of the widespread use of web browsers to deliver content to a large audience across a variety of devices, from desktops and laptops to smartphones and specialized VR headsets, accessibility is essential for expanding the reach of VR and AR technologies. The W3C developed WebXR to extend the capabilities of its predecessor, WebVR, which focused exclusively on virtual reality content [213]. WebXR, by contrast, is designed to support both VR and AR, reflecting the convergence of immersive technologies under the umbrella of XR (extended reality). By building on existing web standards, such as WebGL (for rendering 3D graphics) and WebRTC (for real-time communication), WebXRenables the seamless integration of immersive experiences into the web without requiring users to install additional plugins or extensions. This shift to a more plug-and-play model significantly reduces the friction for users, making VR and AR content as easily accessible as traditional multimedia like videos or interactive maps. In addition to accessibility, WebXR offers significant development efficiencies. By adopting WebXR, developers can create cross-platform VR and AR content without needing to maintain separate codebases for different devices or platforms [236]. WebXR provides a unified API that works across various browsers and devices, making it easier to create device-agnostic immersive experiences. This allows developers to focus on the content and interaction design rather than worrying about compatibility issues across different hardware. Google Chrome, Firefox Reality, and Microsoft Edge fully support WebXR, enabling immersive experiences across a broad range of devices, from Oculus Quest to Microsoft HoloLens, as well as traditional desktop and mobile environments. The increasing demand for web-based XR applications across various industries has also fueled the adoption of WebXR [237]. In e-commerce, for instance, WebXR enables AR product visualizations, allowing users to view 3D models of products in their real-world environment before making a purchase. WebXR facilitates the rapid development of such applications, as it allows businesses to embed AR experiences directly into their e-commerce sites without requiring users to install a separate app. Education and training are other sectors benefiting from WebXR [221]. With the rise of remote learning and virtual classrooms, WebXR enables delivering immersive educational content through standard browsers. Schools and universities can deploy virtual lab simulations, 3D models, and interactive lessons directly on their websites, accessible from any device. This is particularly useful in low-resource environments where schools may not have access to high-end VR hardware but can still provide immersive learning experiences using WebXR on desktop or mobile devices. Healthcare is another industry that stands to benefit significantly from WebXR's accessibility [238]. Medical professionals can use web-based VR simulations to practice procedures or conduct remote AR-assisted diagnostics. For example, WebXR-enabled telemedicine platforms could allow healthcare providers to remotely guide patients through diagnostic steps or deliver real-time AR overlays during consultations. By making such tools available via the web, WebXR expands access to critical healthcare services, particularly in remote or under-served regions where specialized hardware and software may not be readily available.