Software
VATSIM is supported by what has been described as remarkably complex and robust software to allow the operation of the network. This software has allowed the online flying experience to become increasingly realistic with software that closely resembles the screens used in the real world for managing aircraft. Users need custom plugins (such as SquawkBox or FSInn) for flight simulators (such as Microsoft Flight Simulator or X-Plane) to connect as pilots, or radar simulation applications Advanced Simulated Radar Client (ASRC), Virtual Radar Client (VRC) or Euroscope to connect as air traffic controllers. VATSIM-specific applications are available for free and provided by the network itself.
Network service is provided by proprietary servers located throughout the world. All servers are interconnected so that users can see each other on the network, no matter which particular server they connect to.
There are also additional 3rd party tools available that are not essential for the usage of the network, but can provide useful information such as aggregated statistics for airports, route information, and flight history.
Read more about this topic: Virtual Air Traffic Simulation Network