According to Wikipedia, a virtual worldis an online community that takes the form of computer based simulated environment through which users can interact with one another and use and create objects. The term has become largely synonymous with interactive 3D virtual environments, where the users take the form of avatars visible to others.
Virtual World Examples in Education
Second Life - Developed by Linden Labs it is one of the largest and most successful virtual worlds currently in existence. While not developed for education, it hosts a large K-12, higher ed, and education organization presence.
Open Simulator - An open source solution, this free solution can be downloaded onto a web server allowing the creation of a virtual world that can be completely controlled for access, content, etc.
Reaction Grid - One of the most popular and successful worlds using Open Simulator, it has a large education related population.
Active Worlds Education - This powerful virtual world (Windows only) includes a separate grid for education related users, including the River City Project.
Open Wonderland - Build your own virtual world with this Java based open source option.
Immersive Education Initiative - A collaboration of education organizations have developed this non-profit effort to provide a sense of "being there" in virtual education.
ClubPenguin - A virtual world developed by Disney to be a safe online world for children.
Massively Minecraft - A Guild based learning community for kids aged 4-16 who are interested
in developing digital media skills, exploring their creativity and
developing online social skills using the video game Minecraft.
Video (Machinema) from Second Life
Virtual Activities/Simulations - Smaller in scale, simulations are games that simulate a
situation for an experience or purpose without actually being avatar
driven. Many of these are completely online and don't require an
installation. Be aware of the impact on computer resources as well as
Links to Online Simulations
Plan It Green - build and maintain and ecologically friendly environment
Web Adventures - Science and gaming connect to allow students to experience the real work of science in a virtual situation.
Atlantis Remixed & Quest Atlantis
- These two resources are 3D activities that combine gaming and virtual
worlds for students to have an immersive learning experience.