As mentioned before, in general, integrating two multiuser systems will require that each be made ``bus aware'', that is, modified to communicate with the collaboration bus. Often, it is not desirable or possible to change a multiuser system. Therefore, we intend to explore methods for interfacing with the bus that do not require changes to multiuser systems and explore the kind of integration methods that can be supported by these techniques.
So far, we have identified the following techniques: a) No Integration Code: Some integration methods for certain pairs of multiuser systems may not require the writing of new code. For instance, mixing two session management schemes can be done without changing either. b) Unix Pipes: An approach often used in contemporary operating systems for enhancing teletype-based applications is to create a new application that includes the enhancements and interacts with the original application using a UNIX-like pipe. We propose to investigate this approach for teletype-based collaborative systems. c) Pseudo Agents: In our effort on shared window systems, we have had substantial experience with the notion of a ``pseudo server'', that is, a process placed between a client and a real server that pretends to be the real server and processes requests from the client before forwarding them to the real server. We intend to explore the use of this technique for interfacing between server-based multiuser systems and the bus.