Virtual World Research

An Annotated Bibliography

With an Accent on Virtual Pet Virtual Worlds

Information for those studying virtual worlds, developing virtual worlds, writing technical papers, thesis and disertations on virtual worlds. If you are aware of any major virtual world research sources not listed below, please contact us.

If cite some of the references you find here in a technical paper, please cite this page as well.

This page is part of the Virtual Pet Home Page, a Polson Enterprises web site.


A Very Brief History of Virtual Worlds

The initial virtual worlds were text based. The world and your surroundings were totally described by text. The first world, called MUD (Muliti User Dungeon) was created in the late 1970's in England at Essex University.

The game did not really have a dungeon sitting. Zork, a popular single player Fortran game, has a version called DUNGEN. Roy Trubshaw, the creator of MUD, was inspired by DUNGEN and wanted to create a similar multiplayer game. He switched the DUNGEN spelling to DUNGEON, and used it as part of an acronmyn and named his game MUD (Multi User Dungeon). Early versions of MUD were hosted on a DEC-10 computer.

By the mid 1980's, several players started building their own versions of MUD and giving them different names.

None of the early virtual worlds were hosted on personal computers. You had to get on a network (usually a university network) to access them.

Some popular text based MUDs were AberMUD and TinyMUD.

An extensive Chronology of MUDs is available on Wikipedia.

In 1992, a Neal Stephenson science fiction novel, Snow Crash, widely introduced the idea of humans acting as avatars interacting with each other in a 3D space that resembled the real world. He called it the Metaverse.

By the mid 90's, Sceptre of the Goth was running as a PC dial up virtual world. Each game was hosted on a computer in large city in which its users lived.

AOL, Compuserve, and the Internet significantly increased the number of people with access to virtual worlds.

Some early graphical virtual worlds were Meridian59, Ultima Online, Kingdom of the Winds and Everquest (world of Norrath).

A much more extensive history of early virtual worlds is avaialable in the book, Designing Virtual Worlds, by Richard A. Bartle, one of the early MUD developers.

It was only a matter of time till virtual pets began to populate the new media. First, some pet based virtual worlds began to popup, most noteably, Neopets. Then after a while, Ganz introduced the Webkinz model (buy a plush pet in a retail store that bears a secret code, enter the secret code online to enter the virtual world with a virtual model of your retail pet). When Webkinz was successful, others quickly jumped on the model including:

  • Kookeys (Vox10)
  • Ty 2.0 Beanie Babies
  • Russ Berrie's Shinning Stars
  • Ty Girlz
  • Be-Bratz (Bratz dolls)
  • MyePets
  • Rescue Pets (MGA)
  • BuildABearville (Build a Bear)
  • Hasbro's Littlest Pet Shop VIPs
  • SeaPals World from Russ Berrie
  • World of Warcraft (Blizzard Entertainment) has plush pets with secret codes that can be redeemed for online pets
  • Freaky Pets (Abandon Interactive Entertainment in conjunction with Halmark)
  • Neopets added the plush pets to their existing online operation
  • (Webkinz's plush pet manufacturer, the Haili Group in Zhejiang China, runs their own site similar to Webkinz in China. Webkinz in Chinese means Net Doll)

Several other sites followed somewhat similar web hybrid/toy models:

  • Barbie Girls can purchase a special MP3 player, plug it into a PC, then connnect to to unlock VIP content and wear a sparkly tiara (the same VIP content is available to others for a monthly fee).

  • Bella Sara for young horse lovers requires an activation code from Bella Sarah trading cards in order to register.

  • Club Penguin lets you purchase a Puffle Plush with a coin in its pouch at various retail locations. Pull the coin out, enter its "code" in the online game to purchase online items and recieve online coins.

  • In a February 2008 press release, Disney announced a new world, Pixie Hollow, that would introduce "Clickables". Clickables are real jewelry, bracelets, charms, and trinkets with embedded RFID chips that are readable by a USB device (jewerly box) attached to your computer. Clickables will allow increased interaction with their virtual world.

  • In November 2008, Ubisoft announced they would be releasing UbiPetz plush toys with Petz Dogz, Petz Catz Clan, and Petz Monkeyz for Nintendo DS. A code on the plush pets would unlock exclusive UbiPetz items. Now (2010) the codes are entered online to get a secret password that allows you to unlock your virtual pet on your Nintendo DS.

  • In August 2009, Nanovor (Smith & Tinker) initally require the retail purchase of a handheld Nanoscope for enhanced play, then switched to a web only version.

  • In mid 2010, Disney announced a new "World of Cars Online" based on their Pixar film, Cars. Users enter "race codes" off tickets inside specially marked die cast toy cars purchased from retailers to create an account or add cars to their existing account.

  • In early October 2010, Nukotoys announced a virtual world entry based on trading cards, books, and other toys. The operation is in association with Ology books, Animal Planet, and PBS.

Some Virtual Worlds allow avatars to own virtual pets:

  • Habbo Hotel launched in 2000 was one of the earliest graphical virtual worlds that allowed you to outfit your room (hotel room) including having a pet.

  • The Sims Online launched in late 2002 and allowed ownership of virtual pets. Sims Online has since closed.

  • Second Life was launched by Linden Labs in 2003 and allows their "citizens" to have pets.

  • Pets were also possible in some of the MUDs.

Virtual World and Computer Game Acronyms

As MUDs and other computer games developed, a lot of acronyms emerged. Among them are:

    MMO or MMOG - Massively Multiplayer Online Game

    MMORPG - Massively Multi Player Online Role Playing Game

    MOO - MUD Object Oriented (text based online virtual reality system with mulitiple players at the same time)

    MUD - Multi-User Dungeon

    RPG - Role Playing Game

Databases Containing Several Virtual World Papers

In addition to listing databases below, we also provide a list of search terms you may helpful in the next section.

Search Terms

Those researching virtual worlds may find the search terms below helpful.

    Persistent World / Persistent Worlds (an early term for virtual worlds)
    Virtual World(s)
    Metaverse (an early term for virtual worlds)

    MUDs (an early term for virtual worlds)
    MUGs (an early term sometimes used for MUDs)

    Graphical MUDs (early name for visual virtual worlds)

    Virtual Goods
    Persistent playing objects
    Virtual Property
    Virtual Weapons
    Virtual Rooms
    Virtual Furniture

    Player Created Content
    User Created Content
    Persistent playing objects (an early term)


    MUD Multi User Dungeon
    MOO MUD Object Oriented
    MMO Massively Multiplayer Online Game
    MMOG Massively Multiplayer Online Game
    MMORPG Massively Multiplayer Online Role Playing Game
    RPG Role Playing Game

    Snow Crash (book that introduced the Metaverse)

    Virtual Pet Virtual World keywords:
    virtual pet(s) plush toys
    plush animals
    plush pets
    stuffed animals
    virtual dopperganger (tangible double)
    secret code
    web toy hybrids / hybrid web toy

    Phrases that may find Virtual World College Design Projects:
    Senior Design Project
    Capstone Design Project
    Design Project
    Project Class
    Senior Engineering Project

Major Virtual World Papers

By now, their are hundreds of papers discussing virtual worlds. A few really stand out. They are listed below along with some other representative articles:

Virtual World Patents

We list several early virtual world patents on our Virtual Pet Patents Page.

More recent ones and those not dealing with pets can be found on the U.S. Patent and Trademark Office web site using the methods outlined on our How to Conduct a Patent Search page.

If you find a U.S. patent of interest, be sure to check the Public PAIR for more detailed information of how the patent was examined.

Virtual World Books

There are many books on virtual worlds. We only list a few of the very dominant ones below.

  • Designing Virtual Worlds by Richard Bartle. (2004).

  • Synthetic Worlds: The Business and Culture of Online Games by Edward Castronova. (2006).

  • Google Books provides at least limited access to several virtual pet books.

Historical Virtual World News

Some major news sources still contain many of the press releases from the early days of virtual worlds.

  • Google News be sure to click on "archives"

  • Lexis Nexis Academic (available at many major universities)

Current Virtual World News

Virtual World Publications

Additional Resources

  • IGDA International Game Developers Association

  • KZERO virtual world consulting firm that prints several reports and some great radar charts comparing todays virtual worlds and their users.

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