With the increasing adoption of Java for parallel and distributed computing, there is a strong motivation for enhancing the expressive elegance of the RMI paradigm with flexible and adaptable communication substrates. Java RMI is an especially powerful and semantically comprehensive framework for distributed Java applications — but the default Java RMI implementation is bound to a concrete wire protocol, JRMP, that is neither interoperable nor very efficient. To address the first issue, libraries have been proposed that provide RMI semantics over different wire protocols such as SOAP or IIOP, making Java interoperable with Web Services and CORBA. Similarly, alternative high performance RMI implementations have been developed. However, none of these solutions are designed to work cooperatively, and each imposes specific constraints on developers. This paper describes RMIX: an RMI framework that supports a variety of dynamically pluggable wire transports underlying a common and uniform RMI facade. RMIX facilitates dynamic protocol negotiation in loosely coupled parallel and distributed systems, and enables the development and deployment of applications that are multiprotocol by nature. Additionally, RMIX offers some enhancements to RMI semantics that are particularly useful in multiuser environments. We describe the design and preliminary implementation of RMIX, present two prototype protocol providers based on the JRMP and SOAP protocols, and outline a transition path from legacy RMI applications to RMIX.