Abstract. Multi-User Virtual Worlds (MUVW) such as Open Wonderland andOpenSim have proved to be fruitful platforms for innovative educational practice, supporting exploratory learning and generating true engagement. However, when compared with the way educational activities have flourished through the use of the constantly evolving WWW, MUVW learning environments remain a relatively obscure niche. Since the advent and promise of Second Life more than twelve years ago there has been no critical mass reached and no movement towards standardisation. Concomitantly, the 3D Web has emerged as a recognisable if loosely defined concept. With the advent of technologies such as WebGL and a plethora of plug-in 3D viewers for web browsers, the question arises: will MUVWs converge with the 3D Web? If so, can existing educational content be migrated to the 3D Web for mass dissemination? The paper contributes a survey of 3D Web and MUVW terms, concepts, technologies and projects, illustrating their similarities, their value for education and discusses the likelihood of convergence. The survey is complemented by a cultural heritage case study of Unity 3D support for the deployment of virtual worlds in web browsers using two different approaches.