Second Life is a 3D virtual world created by Linden Labs that allows for user-created content and environments. The document discusses reasons for and challenges with teaching English as a second language (ESL) in Second Life. Some advantages include providing vibrant learning environments, opportunities for authentic international communication, and convenience. However, technical issues, learning curves, and institutional constraints can pose difficulties. The document provides several plans and cost structures for setting up ESL classes in Second Life and recommendations for effective teaching strategies using the platform.