This book focuses on one area in the field of Computer-Mediated Communication that has recently exploded in popularity--Virtual Worlds. Virtual Worlds are online multiplayer three-dimensional environments where avatars represent their real world counterparts. In particular, this text explores the potential for these environments to be used for language learning and telecollaboration. After providing an introduction and history of the area, this volume examines learning theories--both old and new--that apply to the use of Virtual Worlds and language learning. The book also examines some of the most popular Virtual Worlds currently available, including a discussion of the strengths and weaknesses of each. The Virtual World of Second Life is explored in depth, including research examining how users of this world are using language there, and how they are using it to enhance their second language skills.