BACKGROUND AND HISTORY
Virtual worlds are online three-dimensional spaces where you can interact with other people, collect items and build structures, and communicate via a virtual representative of yourself called an avatar. These worlds have been influenced by various science fiction writers such as William Gibson and Neal Stephenson, along with the movie, "The Matrix."
Virtual worlds differ from massive multiplayer online games (MMOGs) because they don't offer battles against monsters or have an overriding mission for players. For example, a resident of the virtual world Second Life might spend time in that space accumulating virtual land, rather than striving to complete quests or conquer levels as one would in many popular MMOGs such as World of Warcraft.
The origin of virtual worlds goes back to early games such as Maze War, which was developed in the early '70s at NASA. The game included eyeballs as avatars, there were maps showing the levels, and it was one of the first games played on networked computers, and eventually over a precursor to the Internet.

In 1986, LucasFilm Games developed Habitat, a more two-dimensional environment that included humanoid avatars, and people could access the game through online service Quantum Link on their Commodore 64 computers. Developers Chip Morningstar and Randy Farmer, who maintain a blog about their experience with Habitat, say they let Habitat residents generally set their own rules governing the world -- as long as they couldn't hack into the system. In a research paper about their lessons from Habitat, the developers wrote:
At the core of our vision is the idea that cyberspace is necessarily a multiple-participant environment. It seems to us that the things that are important to the inhabitants of such an environment are the capabilities available to them, the characteristics of the other people