Harpoon III accurately models and simulates Naval and Air Warfare. It models pretty much all aspects of Naval and Air combat: Ships, Subs, Aircraft (fixed-wing and rotary, aka helos), Missiles, Torpedoes, Gunfire, Radar, Sonar (passive and active).
Ground Warfare is partially modeled (only stationary ground units are modeled, such as Air Bases, Anti-Air Weaponry, and similar objects…Air Bases, and other large abstract objects, such as cities, are modeled as groups of smaller items: Runways, Hangars, Control Towers, Radars, AAGuns, etc.).
It is based on Harpoon II (aka, Harpoon2), with many bug fixes and improvements. Harpoon II was based on the Harpoon wargame rules created by Larry Bond.
The interface is a windowed Graphical User Interface, with graphics modeled after those found on modern US Navy war ships. All game related graphics are Vector Graphics (that is, drawn with lines), with two exceptions: the Platform Database, which has BitMapped graphics of many Units in the game (that is, pictures); and the in-game videos (movies of real combat units in action).
More info and download link here.