For the better part of the past quarter century, the defense simulation industry has invested significant resources in technologies and methods for making independently developed simulations work together at run-time. Many reasons for this activity exist. The initial impetus was the need for a common “synthetic environment” that could interconnect simulators in support of small-team training-such environments are now commonplace to today’s online gamers. Subsequently, the notion of “moving electrons to the

people” rather than “moving people to the electrons” led to a proliferation of geographically distributed simulation-based training environments. In addition, there was the belief that each Service (e.g., Army, Navy, Air Force, and Marines) could best model that Service’s capabilities, and if you needed to access such capabilities, you should do so by interconnecting with that Service’s “authoritative” simulations. And of course, the notion of cost savings through simulation reusability also drove the development of technologies for simulation interconnection. Today, simulation interconnection is pervasive in the defense simulation arena.