ATC-pie
Air traffic control tower and radar simulator (solo + multi-player)
ATC-pie is an air traffic control simulation program. It features solo, multi-player and teacher-student sessions, rendering 3D views of airports through FlightGear. It is essentially designed for realism, and simulates real-life ATC tasks and equipment such as strip racks and sequence management, handovers to/from neighbouring controllers, flight plans, primary & secondary radars, RDF, CPDLC, ATIS recording...