We have developed a desktop meeting environment named FreeWalk that supports casual meetings in a 3-dimensional (3D) virtual shared space, community common. Tools for human communicadons are always required to run at a practical speed in a widely-used non-luxury hardware environment. However, in the previous researches on 3D conferencing systems, such as VRML-based systems, this aspect has been sometimes neglected. Though we need a research testbed for investigating human-human interactions, researchers tend to concentrate on advanced 3D technologies. In the area of videogames, on the other hand, where 3D virtual spaces are also provided, technologies used there successfully achieve an attractive presentation under severe hardware constraints. Therefore, in the development of FreeWalk. we have applied videogame technologies especially to friendly interface and efficient visualization, so to realize casual communications in a network.