Living Worlds (LW) is a Working Group of the VRML Consortium, supported by a 
  large number of organizations. The LW effort aims to define a set of VRML 2.0 
  conventions that support applications which are multiuser and interoperable. 
  Scenesharing", which is concerned with the coordination of events 
  and actions across the network, is one of the main elements of LW. In short, 
  LW is a first attempt to devise a common VRML 2.0 interface to support basic 
  interaction in multi-user virtual scenes and enables each participant to know 
  that someone has arrived, departed, sent a message or changed something in the 
  scene.
 Although LW specifies rules for object sharing and exchanging 
  update messages across the network, it is not a communications middleware
  and the reason it is being presented in this section is that it is also not 
  concerned with graphics and rendering. In fact LW does not care about the actual 
  technical implementation of the communications system that enables world sharing. 
  Referred to as the Multi User Technology (MuTech), the actual system that runs 
  on the network and is responsible for message passing among clients can be developed 
  by any technology as long as its interface to the VRML world follows the LW 
  specifications. Currently no implementations of LW are publicly available.