The goal of this paper is to investigate the basic principles of a tele-immersive system, its main components, development history, demonstrations and potential uses as one of today's most challenging technologies which takes all our knowledge of virtual reality, networks, haptics etc to the limits and beyond. Ultimately the paper presents a future research and development roadmap for this technology. Tele-immersion involves combining teleconferencing, tele-presence and virtual reality to allow individuals to manipulate a shared environment, converse, interact and even see each other. But the ultimate objective of tele-immersion is not solely to reproduce a real face-to-face meeting in detail, but also to provide the interface for collaborators, world-wide, to work together in a shared virtual environment, even though they may be miles apart physically. Tele-immersion stands at the crossroad of researches related to virtual reality and networking, computer visualization and user interfaces and can be said to unify all of these research areas. ...