Don't know of anything like this, but this is a really good idea! It would be sweet to have a scene and renderer with well-known properties (which could be adjusted to account for style; realistic/toon/dynamic lighting/baked lighting, etc) which could be dropped in to a webpage so that users could mess with it. That way, developers could independently include it and write their own ways of injecting the assets.
The end result being a web widget that is a 3D environment with whatever the developer wants to put in it (with some defaults like "sunny outside", "sun room", "basement", "cave", etc), and drag-and-drop asset selection for users to view the showcased assets in the scene. Could even double as a code-guide, based on your idea of including functioning TV and Radio assets (an example of how to include this functionality into the assets). Overall, just a really great idea!
The end result being a web widget that is a 3D environment with whatever the developer wants to put in it (with some defaults like "sunny outside", "sun room", "basement", "cave", etc), and drag-and-drop asset selection for users to view the showcased assets in the scene. Could even double as a code-guide, based on your idea of including functioning TV and Radio assets (an example of how to include this functionality into the assets). Overall, just a really great idea!