Babel is a high-performance, n-way language interoperability tool for the HPC community that now includes support for distributed computing via Remote Method Invocation (RMI). We describe the design and implementation of Babel RMI, including its specification in our Scientific Interface Definition Language (SIDL), modifications to Babel’s code generators, and support for third-party wire protocols. Babel RMI’s programming model consistency, functional capabilities, and runtime performance are compared in context with COM, CORBA, Grid/Web Services, and Java RMI. Babel RMI’s current features and performance uniquely recommend it for “short-haul” distributed computing within a machine room or single cluster. We describe the experience of some early adopters who use Babel RMI to couple and coordinate multiple MPI jobs on a single cluster to perform multiscale material science calculations.