X-Plane is the world's most comprehensive, powerful flight simulator, and has the most realistic flight model available for personal computers.
Welcome to the world of props, jets, single- and multi-engine airplanes, as well as gliders, helicopters and VTOLs such as the V-22 Osprey and AV8-B Harrier.
X-Plane comes with subsonic and supersonic flight dynamics, sporting aircraft from the Bell 206 Jet-Ranger helicopter and Cessna 172 light plane to the supersonic Concorde and Mach-3 XB-70 Valkyrie. X-Plane comes with about 40 aircraft spanning the aviation industry (and history), and several hundred more are freely downloadable from the internet.
X-Plane scenery is world-wide, with scenery for the entire planet Earth AND MARS! (thanks to the Mars Orbiting Laser Altimeter, which mapped that planet's elevation) You can land at any of over 18,000 airports, as well as test your mettle on aircraft carriers, helipads on building tops, frigates that pitch and roll in the waves, and oil rigs.
Weather is variable from clear skies and high visibility to thunderstorms with controllable wind, wind shear, turbulence, and microbursts! Rain, snow and clouds are available for an instrument flying challenge, and thermals are available for the gliders! Real weather conditions can be downloaded from the internet, allowing you to fly in the actual weather that currently exists!
X-Plane also has detailed failure-modeling, with 35 systems that can be failed manually or randomly, when you least expect it! You can fail instruments, engines, flight controls, and landing gear at any moment.
While X-Plane is the world's most COMPREHENSIVE flight sim, your purchase also comes with Plane-Maker (to create your own airplanes) World-Maker (to create your own scenery), and Weather Briefer (to get a weather briefing before the flight if you use real weather conditions downloaded from the net).
X-Plane is also extremely customizable, allowing you to easily create textures, sounds, and instrument panels for your own airplanes that you design or the planes that come with the sim.
X-Plane's accuracy (in flight model), scope (in aircraft and terrain coverage), versatility (in aircraft type and weather conditions), add-on programs (in aircraft and scenery editors), user-customizability, downloadable aircraft, and downloadable scenery makes it the ULTIMATE flight simulation experience for Macintosh AND Windows platforms.
Source: Archived Publisher Website.
Significant changes for this version included a new game engine, .png texture format, and icon.
Source: Wikipedia, "List of X-plane releases", available under the CC-BY-SA License.