The term 'Metaverse' has taken on new interest recently, appearing prominently in the marketing materials of a number of large technology companies. Indeed, many have attempted, or are attempting, to co-opt it for their own purposes, which has resulted in a great deal of confusion among producers and consumers in the marketplace. With this paper, the Web3D Consortium seeks to address this confusion by exploring the history of the 'Metaverse', provide a workable definition of the term 'Metaverse', and provide a vision for its sustainable, cooperative construction into the future. We believe that all the technologies are in place to fulfill the vision of an open, equitable, and ubiquitous information space. What remains are the key issues that have kept the Metaverse from manifesting the last two decades: poor user experience and poor corporate cooperation.