This document discusses the 3D internet and virtual worlds. It begins with an introduction and overview of the 3D internet. It then discusses why the 3D internet is needed by explaining how cyberspace is a virtual environment for interaction. It describes how the 3D internet works using platforms like Second Life that allow users to interact through avatars. Technical issues and applications are discussed along with programming languages used to develop for the 3D internet like VRML and WebGL. The document concludes that the 3D internet provides an interactive and engaging experience for connecting with others.