1. An Internet-based system for implementing massive groupware applications, comprising: a plurality of computer-based clients, each client including a processor and memory with instructions stored in the memory and executed by the processor to implement a groupware application; one or more repeater routers, each repeater router being operative to receive input data packets from at least one of the clients and perform the following functions: decode the input data packets and replicate the packets in accordance with a set of rules, and forward the replicated packets as output data packets to other clients based upon a connection protocol; and one or more lobby managers providing and updating the rules and connection protocol to each repeater router so that each repeater router only forwards packets to relevant clients associated with the groupware application; and wherein the set of rules includes a rule that each client may continuously predict where an object simulated by another client will be absent of control input, and if the error associated with the prediction is sufficiently small, the repeater router need not forward any state change packets from source client to destination client.