Wikipedia
OpenEaagles is an open source framework designed to support the rapid construction of virtual (human-in-the-loop) and constructive simulation applications. It has been used extensively to build DIS compliant distributed simulation systems. It is based upon Eaagles, a popular simulation framework developed and maintained by the U.S. Air Force to support a multitude of simulation activities.
Serving as a simulation design pattern it provides a structure for constructing simulation applications. The framework aids the design of robust, scalable, virtual, constructive, stand-alone, and distributed simulation applications. It leverages modern object-oriented software design principles while incorporating fundamental real-time system design techniques to meet human interaction requirements.
By providing abstract representations of system components (that the object-oriented design philosophy promotes), multiple levels of fidelity can be easily intermixed and selected for optimal runtime performance. Abstract representations of systems allow a developer to tune the application to run efficiently so that human-in-the-loop interaction latency deadlines can be met. On the flip side, constructive-only simulation applications that do not need to meet time-critical deadlines can use models with even higher levels of fidelity.
The framework embraces the model-view-controller (MVC) software design pattern by partitioning functional components into packages. This concept is taken a step further by providing an abstract network interface so custom protocols can be implemented without affecting system models. Examples include the Distributed Interactive Simulation (DIS) protocol interface.