One of the ways of cutting down on the cost in bandwidth of implementing a space is to move as much of the space as possible onto the user's machine. On any Net surfer's machine one can find a host of client applications: web browsers, news readers, mail readers, conferencing software, etc. Most of these are simply interfaces between the operating environment of a particular machine and the intermachine protocols, but some (Worlds Chat, for example) can reach a point of complexity where more of the "action" takes place on the user's machine than the host's (which takes a passive role akin to the moderator of a debate).
