The Metaverse is a collective virtual shared space, created by the convergence of virtually enhanced physical reality and physically persistent virtual space,  including the sum of all virtual worlds, augmented reality, and the internet. The word metaverse is a portmanteau of the prefix " meta " (meaning "beyond") and " universe " and is typically used to describe the concept of a future iteration of the internet, made up of persistent, shared, 3D virtual spaces linked into a perceived virtual universe.
The term was coined in Neal Stephenson's 1992 science fiction novel Snow Crash , where humans, as avatars, interact with each additional and software agents, in a three-dimensional space that uses the metaphor of the real world. Stephenson used the term to describe a virtual reality -based successor to the Internet. Concepts similar to the Metaverse have appeared under a variety of names in the cyberpunk genre of fiction as far back as 1981 in the novella True Names . Stephenson stated in the afterword to Snow Crash that after finishing the novel he learned about Habitat , an early MMORPG which resembled the Metaverse.
Developing technical standards for the Metaverse
Conceptually, the Metaverse describes a future internet of persistent, shared, 3D virtual spaces linked into a perceived virtual universe, but common standards, interfaces, and communication protocols between and among virtual environment systems are still in development. Several collaborations and working groups have been established in an attempt to create the types of standards and protocols that would be needed to support interoperability between virtual environments, including:
- Virtual Worlds - Standard for Systems Virtual Components Working Group (P1828),  IEEE (2010–Present)
- Information technology—Media context and control—Part 4: Virtual world object characteristics (ISO/IEC 23005-4:2011),  ISO (2008–Present)
- Immersive Education Technology Group (IETG),  Media Grid (2008–Present)
- Virtual World Region Agent Protocol (VWRAP),  IETF (2009–2011)
- The Metaverse Roadmap,  Acceleration Studies Foundation (2006–2007)
- The Open Source Metaverse Project, (2004–2008)
Many of these working groups are still in the process of publishing draughts and determining open standards for interoperability.
Timeline of virtual environments inspired by the Metaverse concept
Since Stephenson's novel appeared, improvements in internet technology, bandwidth, and computational power permitted real-life implementations inspired by the concept of the metaverse to develop. A brief timeline of notable platforms and developments include:
- 1993 - was launched, a MOO (a text-based, low-bandwidth virtual reality system) by Steve Jackson Games as part of their BBS, Illuminati Online.
- 1995 - Active Worlds , which was based entirely on Snow Crash , popularised the project of creating the Metaverse by distributing virtual-reality worlds capable of implementing at least the concept of the Metaverse.
- 1998 - There was created, wherein users appear as avatars and, in addition to socializing, could purchase objects and services using the virtual currency therebucks , which were purchasable with real world money. There.com closed on March 2, 2010, but reappeared in 2011 as an invite-only world to users age 18 or older.
- 1998 - blaxxun was created 3D virtual communities that using the vrml technology. like: cybertown and Jewel of Indra.
- 2003 - Second Life was launched by Linden Lab. The stated goal of the project is to create a user-defined world like the Metaverse in which people can interact, play, do business, and otherwise communicate.  It is usually used from a third-person perspective (although first-person "mouselook" is available), and its current technology (like the others listed here) doesn't yet allow the photo-realistic environment described in the Metaverse of the book. 
- 2004 - X3D was approved by ISO as the successor to the Virtual Reality Modeling Language ( VRML) as the open standard for interactive real-time 3D ( web3D). Today X3D is the standard defining the 3D web and mixed reality Open Metaverse by combining virtual, mirror, and augmented realities with the web.
- 2004 - IMVU, Inc. was founded by Will Harvey, Matt Danzig and Eric Ries. It started out as an instant messenger with 3D avatars and has after expanded and evolved.
- 2005 - Solipsis launched, a free open source system aiming to provide the infrastructure for a Metaverse-like public virtual territory.
- 2005 - The Croquet Project began as an open source software development environment for "creating and deploying deeply collaborative multi-user online applications on multiple operating systems and devices",  with the aim of being "more extensible than the proprietary technologies behind collaborative worlds such as Second Life".  It was used to build virtual worlds such as the ', but after the release of the Croquet SDK in 2007, the project changed names and became the Open Cobalt project.
- 2006 - Entropia Universe, the world's first real cash economy MMORPG.
- 2007 - Several social networks developed to provide profiles and networking capabilities for metaverse avatars, including Koinup, Myrl, AvatarsUnited. These projects faced a large number of challenges related to the lack of DataPortability of the Avatar across a large number of virtual worlds and attempt to address the possibility of managing multiple accounts on a single dashboard. (AvatarsUnited was later purchased by Linden Lab, and then shut down when a few social networking features were added to the SecondLife.com Website.)
- 2007 - OpenSimulator appeared,  developing free open-source virtual world software that's protocol-compatible with Second Life but allowing user movement between otherwise independent installations.
- 2008 - Google Lively was unveiled by Google through the Google Labs on July 8, 2008.  It was intended that new features would be added over time, but on November 19 2008, it was announced that the Lively service would be discontinued at the end of December.
- 2017 - Decentraland , the world's first decentralized virtual reality world in which players actually own the land within the game.
It should be noted that various massively multiplayer online games bear a resemblance to elements of the Metaverse, although they typically focus on specific gaming purposes rather than socializing.
Stephenson's Metaverse in Snow Crash
Stephenson's Metaverse appears to its users as an urban environment, developed along a single hundred-meter-wide road, the Street, that runs the entire 65536 km (2 16 km) circumference of a featureless, black, perfectly spherical planet. The virtual real estate is owned by the Global Multimedia Protocol Group, a fictional part of the real Association for Computing Machinery, and is available to be bought and buildings developed thereupon.
Users of the Metaverse gain access to it through personal terminals that project a high-quality virtual reality display onto goggles worn by the user, or from low-quality public terminals in booths (with the penalty of presenting a grainy black and white appearance). Stephenson additionally describes a sub-culture of people choosing to remain continuously connected to the Metaverse by wearing portable terminals, goggles and additional equipment; they're given the sobriquet " gargoyles " due to their grotesque appearance. The users of the Metaverse experience it from a first person perspective.
Within the Metaverse, individual users appear as avatars of any form, with the sole restriction of height, "to prevent people from walking around a mile high". Transport within the Metaverse is limited to analogues of reality by foot or vehicle, such as the monorail that runs the entire length of the Street, stopping at 256 Express Ports , located evenly at 256 km intervals, and Local Ports , one kilometre apart.