Multi-player classic air combat simulator

 A multi-player aerial combat simulation. Players engage in air to air
 combat against one another using heat seeking missiles and cannons.
 .
 Main features include:
  * Simulation with 6 degrees of freedom.
  * Tricycle and bicycle landing gear simulation.
  * Structural limit to the vertical positive/negative load.
  * Standard atmosphere.
  * Weather: daylight/night, fog, wind.
  * Classic instruments, including magnetic compass, turn and slip
    indicator, airspeed indicator, attitude and bank indicator,
    altitude indicator, vertical speed indicator.
  * Navigation: HSI with RNAV calculator, ADF.
  * Head-up display (HUD) and inertial reference system.
  * Auto-pilots: hold altitude, hold climb rate, hold speed, follow VOR
    radial, follow ILS glide path, rudder/ailerons coordination.
  * Several aircraft models implemented, both civil and military.
  * Two sceneries provided: Dallas area (Texas) and Italy area with
    hundreds of runways and radio stations.
 .
 acm runs under the X window system. This version of acm is
 implemented as a distributed simulation. It communicates information
 via the IEEE Distributed Interactive Simulation protocol.
 .
 The original version of acm was written by Riley Rainey. This is
 Umberto Salsi's updated version.