Terra Nova is a collaborative weblog experiment. It is about an emerging social phenomenon called “virtual worlds” — computer-generated, persistent, immersive, and representational social platforms. Currently, the most popular virtual worlds are massively multiplayer online roleplaying games (MMORPGs), such as Everquest and Star Wars Galaxies. However, there are many other old and new varieties of virtual worlds. Posts at Terra Nova will offer news and opinions regarding the social, economic, legal, psychological, and political aspects of these worlds. They will feature scholarship, insights, and data relevant to the study of virtual worlds. This has been added to Social Informatics Subject Tracer™ Information Blog.