The document discusses the history and concepts of Web 2.0 and virtual worlds, and their potential applications for education. It outlines some of the key components and movements in Web 2.0 like blogs, wikis, social networking sites, and user-generated content. It also discusses early virtual worlds and their precursors. The document then explores some pedagogical approaches and issues to consider when using Web 2.0 and virtual worlds for education, such as principles of distributed conversation and collaborative writing.