A Virtual World is a computer-based simulated environment intended for its users to inhabit and interact via avatars. These avatars are usually depicted as textual, two-dimensional, or three-dimensional graphical representations, although other forms are possible (auditory and touch sensations for example). Some, but not all, virtual worlds allow for multiple users.

The computer accesses a computer-simulated world and presents perceptual stimuli to the user, who in turn can manipulate elements of the modeled world and thus experiences telepresence to a certain degree. Such modeled worlds may appear similar to the real world or instead depict fantasy worlds. The model world may simulate rules based on the real world or some hybrid fantasy world. Example rules are gravity, topography, locomotion, real-time actions, and communication. Communication between users has ranged from text, graphical icons, visual gesture, sound, and rarely, forms using touch and balance senses.

Links:

http://www.virtualworldsreview.com/info/categories.shtml

http://www.virtualworldsnews.com/

http://virtualworlds.nmc.org/

http://www.virtualpublichealth.com/

http://muve.gse.harvard.edu/muvees2003/index.html

http://swi.indiana.edu/index.htm

http://www.barbiegirls.com/home.html

http://secondlife.com/

http://secondlifegrid.net/programs/education

http://www.simteach.com/simteach12_06.pdf

http://facstaff.elon.edu/mconklin/pubs/glshandout.pdf

http://www.sloodle.org/

http://www.forterrainc.com/

http://www.multiverse.net/

http://www.monumentalgames.com/

http://worldforge.org/

http://www.opensimulator.org