This workshop will provide an overview of the systems engineering issues with regard to integrating disparate military simulations for analysis, training, testing, and other purposes.  We will discuss the three major interoperability techniques, the Distributed Interactive Simulation (DIS), the High Level Architecture (HLA) for Modeling and Simulation, and the Test and Training Enabling Architecture (TENA), including descriptions of their architectures and some of their use cases.  Recent and planned evolution of each architecture will be explained. A discussion of how these architectures are actually used in the real world and the process for integrating disparate systems in a multi-architecture environment will be discussed.  The format of the workshop will be part lecture and part informal discussion/question answer.  Participants are encouraged to raise specific topics any time during the workshop.