The High Level Architecture (HLA) is general purpose architecture for simulation reuse and interoperability. The HLA was developed under the leadership of the Defense Modeling and Simulation Office (DMSO) to support reuse and interoperability across the large numbers of different types of simulations developed and maintained by the DoD.

Since the HLA is an architecture, not software, use of runtime infrastructure (RTI) software is required to support operations of a federation execution.

VisiTech engineers are experts at federation development, the HLA architecture, and use of the RTI. The RTI software provides a set of services used by federates to coordinate their operations and data exchange during a runtime execution.