Microsoft have stopped producing Flight Simulator, but DVDs may still be found at some outlets.
An enhanced FSX is available on Steam, and Lockheed Martin have developed Prepar3D.

 FSX and P3D
FSX-Steam Edition Microsoft Flight Simulator X Steam Edition (FSX-SE) offers improved multiplayer options and updated Windows 10 support. Developed by Dovetail Games. It is believed that a new Steam version/product is in the process of being developed. FSX Steam Edition
News, updates, articles and a shop from FSX Steam Edition developer Dovetail Games who acquired licenses from Microsoft to develop FSX for a future release, and to develop it for Steam. Dovetail Games is a trading name of FSX-SE Insider
FSX-SE Community Read articles, lesson and tips from the FSX-SE user community on the Steam web site. Steam FSX Community
P3D version 3 (details) is the flight/sea/land sim by Lockheed Martin. It extends development of the Microsoft ESP (Enterprise Simulation Platform) used in FSX with improvements and greater stability, while maintaining compatibility. [Unofficial, optional payware migration tool (not fully working for v3)] My v3 screenshots...
Official Lockheed Martin P3D support and discussion forums. They include specific forums for discussing issues with installation, normal and multiplayer use, hardware, SimConnect, screenshots. Prepar3d Forums
 Prepar3D Learning Centre & SDK Access the official Prepar3D Learning Center and SDK here. Learning Center offers users helpful information on aircraft, controls, navigations, missions, views etc. SDK sets out parameters for developers and describes use of built-in utilities and plug-ins. Prepar3d SDK
Popular News and Download Sites
Flight sim blog by D'André Newman. News, reviews, comics, interviews and other related material on PC flight simulation from developers and publishers around the world. Plenty of comments and screenshots. Also on Facebook. Pre-2014 Archive
Avsim A huge and popular flight sim portal with thousands of downloads for current and earlier versions of MSFS and other flight sims. News, reviews and many active forums. Totally free. Donations welcome.
 FlightSim Central A flight sim news site. News from developers and publishers around the world, reviews and other flight simulation material. Members have the chance to win giveaways. A number of exciting new features are being developed for this relatively new site. Flightsim Central
The original. A huge flight simulator archive with well over 100,000 files covering all versions of MSFS and P3D. Free, fast downloads, latest news, reviews & active forums. Subscription option gives assured entry and even faster downloads. Recommended.
Fly Away Simulation Flight simulation news and reviews, downloads, forums, FAQs, navigation tutorials, screenshots and links. Completely free FSX, FS9 and X-Plane download libraries and active forums. An optional monthly or yearly subscription gives faster downloads. German language on-line flightsim magazine largely staffed by a group of young volunteers. They carry news, reviews of freeware and payware, articles and videos. Also forum and links.
FSDeveloper Community portal for add-on developers to provide a friendly place where you can discuss your design problems or ideas, whether a commercial or freeware designer, newbie or expert. Covers aircraft, scenery and FSX's missions and SimConnect.
FS Freeware.
Freeware aircraft, scenery and tools downloads for FS2004 and FSX. Also downloads for Prepar3D and Flight Gear.
 Google+ Communities A selection... Frooglesim Microsoft Flight Simulator - FSX Flight Simulator Hangout Community Microsoft Flight Simulator X FSX 模擬飛行論壇 Flight Simulator Flightsim Addicts Flight Simulator Network • There are others...
Hovercontrol Aimed at increasing the unity between the helicopter enthusiasts using MSFS. Offers forums, pilot training, excellent helicopter-related file downloads, screenshot galleries, etc.
Rikoooo A collection of freeware downloads for FS9, FSX and P3D. Includes aircraft, scenery and utilities. Also screenshots and videos. Optional, low cost, paid subscription gives much faster downloads. French and English language. Rikoooo
SimFlight English portal of a large network of useful international sites (France, Spain, Russia, Germany, Poland, Japan etc. each in their own language). Has up-to-date FS news, reviews, a large number of general and product forums, links and an on-line shop. SimFlight
Simviation Gigabyts of quality freeware add-ons nicely organised by type. Includes aircraft, panels, scenery & help with installing them, news, reviews, VA message board.
SurClaro Flight Simulations Large, long established flight simming resource offering thousands of freeware and shareware downloads (free registration required), forums, chat rooms and screenshots. Also hosts an on-line shop. Founded in October 2014, we strive to provide you with daily flight simulation-based updates and content from editors and software publishers from around the globe. Breaking news, exclusive content, reviews, screenshots. V-Aviation
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