X-Plane
As a company concerned with the mechanics in general, very passionate about Formula 1, motor and aircraft in the search for a flight simulator for Apple Mac, we came across this product that we did not know: X-Plane.
The feature of this software that distinguishes it strongly from other flight simulators, is the logic with which the calculation is done by numerical simulation.
In general, all flight simulation software, are based on principles of basic physics, which is why the airplane could be a "cube" with the parameters of a jet fighter F-22 Raptor and fly the same against the laws of physics.
X-Plane instead relies on CFD model calculations, where the air and space elements to interact with finite volume, and then to fly, in addition to the basic parameters is essential to know the shape of the aircraft itself.
This simulator is actually as popular as the MS Flight Simulator, but has the distinct advantage of being cross platform (Mac OS X, GNU / Linux and Windows) and highly customizable having available an SDK (Software develipment = kit) for action a world of add-ons.
The level of customization is one that includes an editor of planes and scenarios, and really lets fly the vehicle of your dreams even if it is not included in the basic package. Surfing on the Internet you can find a lot of air, scenery and plugins.
http://x-plane.com - site based
http://x-plane.org - forum and source for aircraft / scenarios and plugins developed by third parties
http://xplane.it - including the Italian reference scenarios of the main Italian airports

