Publication
The Web of Worlds – Towards a Referential Architecture for Open Spatial Worlds
Holger Graf; Johannes Behr; Alain Pagani; Tracey Swales; Nicholas Polys
In: 2026 IEEE International Symposium on Mixed and Augmented Reality Adjunct (ISMAR-Adjunct) - Workshops. International Workshop on Advancing Interoperability in Virtual Worlds (XWORLDS-2026), located at IEEE ISMAR 2026, October 6, Bari, Italy, IEEE Xplore, 2026.
Abstract
This paper formalises the Web of Worlds (WoW) initiative as a Web‑native architectural framework for cross‑world XR experiences that enables 3D spatial content to break free from existing technological silos, building on the Metaverse Standards Forum's (MSF) 3D Web Interoperability work. The presented work derives requirements from the current research initiatives on interoperability frameworks for XR and the requirements set out within the EU Virtual Worlds partnership and the MSF, by showing how existing web standards and technologies might be able to deliver open spatial worlds and interactive experiences across decentralised platforms. The position paper presents a referential 3D web architecture specifying an Open Spatial Worlds (OSW) API, a lightweight glue layer that exposes linked spatial assets and linked spatial experiences over existing Web and 3D formats (X3D, glTF, USD, OGC APIs). The paper further introduces the “Digital You” manifest and 3D Web user agent as a user‑centred runtime for portable identity, consent and accessibility, and define an interoperable AI endpoint model based on MCP for spatial perception and agentic assistance. An initial implementation in industrial digital‑twin pilots demonstrates already a basic cross‑engine interoperability and runtime performance, providing the XWorlds community with a concrete, standards‑aligned basis for Web 4.0 virtual worlds. We discuss limitations and open research questions for large‑scale deployment.