As far as I can see x3d has almost lost out to gltf [0] which is closer to the hardware and thus provides more rendering options [1], though x3d is sometimes se

As far as I can see x3d has almost lost out to gltf [0] which is closer to the hardware and thus provides more rendering options [1], though x3d is sometimes seen as a "higher-level abstraction" [2] its questionable whether this makes it any easier to approach. It does allow for things like scripting, audio, video, and interactivity pretty natively and can include gltf within but I'm not sure how many applications really go down this route. A good example is 3d tiles specification [3][4] which is fast becoming a default for web and is basically gltf wrapped in json. [0] https://trends.google.com/trends/explore?date=all&q=x3d,gltf https://trends.google.com/trends/explore?date=all&q=x3d,gltf [1] https://realism.com/blog/gltf-x3d-comparison https://realism.com/blog/gltf-x3d-comparison [2] https://www.web3d.org/blog-integrating-x3d-and-gltf https://www.web3d.org/blog-integrating-x3d-and-gltf [3] https://docs.opengeospatial.org/cs/18-053r2/18-053r2.html https://docs.opengeospatial.org/cs/18-053r2/18-053r2.html [4] https://github.com/CesiumGS/3d-tiles/tree/main/specification https://github.com/CesiumGS/3d-tiles/tree/main/specification