Environment, Weather, Water and Lighting
A2A
Simulations
 Home of 3D Lights REDUX aircraft lighting system which casts realistic light out into 3D space, creating stunning visuals and a more immersive flying experience. Installs to default and third party add-on aircraft.
Cielosim Producers of Flight Enhancer and Instant Enhancer for FS9 which improve many of the original texture and effects. Also Live ATC Chatter. Airport Enhancer HDX for FSX to improve runways, taxiways, marking and signs, grass, wet and other textures.
 CumulusX! CumulusX! by Peter Lürkens, creates a thermal environment in FSX for virtual gliding. It creates thermal lift with appropriate clouds either on the fly with a wide variety of characteristics, or based on customised lists of thermals. Also other glider utilities.
FS Global Real Weather FS Global Real Weather is a easy to use, weather engine for FSX, FS9 (2004) and Prepar3D. Delivers weather calculated from more than 24,000 land- and sea-based real world stations. Also calculates air masses and temperatures for upper air levels.
FS Meteo Interfaces with all versions of MSFS, CS2 and Prepar3D, detects where the plane is, reads the weather from the Internet and modifies the weather parameters. Weather gauges also available. Shareware. FS Meteo version 9 released.
FS Water Configurator Modifies FSX seas. Increases the realism of the reflections and lighting of the water and is fully controllable; choose subtle or glass-like reflections. Works with default and third-party textures. Also free Caribbean scenery packs and beach texures.
FSrealWX lite Weather add-on for FS2002, FS2004 and FSX. It decodes METAR and upper wind data (additional weather information such as types of clouds are in preparation) and sends it to the flight simulator.
HiFi
Technologies

(Active Sky)
Home of Active Sky, designed specifically for FSX with Prepar3D soon. Features include smooth visual cloud transitions, on and offline use, dynamic processing, wake turbulence and a radar display. Also Active Sky Evolution and XPax and X Graphics for FS9 & FSX.
 Open Clouds A weather programe that improves the look of cloud and fog coverage in FSX and extends the distance views of clouds. Also works with Rex textures, and Prepar3d. Free for UK coverage, small change for the rest of the world.
OPUS
FSX
Interface for FSX and Prepar3D with Live Weather Engine for real world weather, Live Camera for view control & dynamic head movements, & Live View for synchronized multi-screen networked displays. Payware with demo version available.
REX Real Environment Xtreme is a popular weather engine for FSX. It has an advanced  live, real weather engine and provides the virtual pilot with not only challenging weather, but also radar tools to avoid the weather and enhanced cloud and water textures.
Zinertek Technologies Producers of Ultimate Night Environment, World Environment Pro, Ultimate Water, & Ultimate Airport Environment. These FSX and FS9 sceneries enhance the night, day and airport textures worldwide. World Environment 2012 published.
AI Aircraft & Vehicles
AI-Aardvark AI Aardvark is committed to providing high quality, frame rate friendly aircraft for use with AI traffic. As seen in UTII.
AI
Flight Planner
AI Flight Planner is a fully-integrated, TTools format-compatible AI flight planning tool for Microsoft Flight Simulator, both FS9 and FSX versions. Aircraft may be assigned directly from FS9 or FSX aircraft folders.
AI
Traffic Mover
AITM includes several tools to make FS AI Traffic even more realistic. With AITM it's easy to rearrange, move, export, analyze, and edit aircraft. You can create projects with different flight plans and merge them. New version.
AirNav
FS Live Traffic
An award winning, proram and "subscription service" that loads specific AI traffic all across the world 24x7 based on real word schedules and FAA data and combining that data with an included, special version of My Traffic X. For FSX.
 Airport AI Enhancer Gunnar Daeling's Airport AI Enhancer X (Freeware) helps you to fix the problem of empty aprons at your favorite airports. FS9 version too.
Air Traffic
Editor X
 A great tool to organize AI-traffic or to customize or correct AI-traffic packages. Compatible with World of AI. 30-day free trial version available. AI Traffic Editor X can convert flight plans, and detect errors, such as lack of parking positions.
AlphaIndia We are a group of Flight Simulator fans who want to put the fun back into AI. Our team includes many enthusiastic individuals. Aircraft models (Antonov, Boeing, McDonnell Douglas, CRJ etc,) repaints, flight plans and AFCADs. Forum.
Doug's Flights of Fancy AI repaints and some interesting flight plans and AFCADs for statics at various location, civil and military, including the famous airliner boneyard at Kingman Airfield, Arizona. For FS9. Also videos and links.
MAIW
(Military AI Works)
MAIW (Military AI Works) produce packages of military AI aircraft. Aircraft and Sets cover many countries of the world and offer a huge range of aircraft from fighters, to heavy lift, to helicopters.
My Traffic X Professional MyTraffic X Professional enhances FSX and Prepar3d with realistic, worldwide AI traffic. Includes airliner, general and military traffic in over 2,500 liveries, flying 3.7 million weekly flights and an AI traffic editor. You can select various eras too.  Forum.
Retro AI
Traffic Group
Source of vintage flight plans, AFCAD files, and resources. All of our flight plans are meticulously developed using the finest resources and tools to ensure quality and realism. Web site is down, see forum for screenshots and links to files.
Super Traffic Board Airport style flight info board for FSX and Prepar3D that supports all AI packages. Real time advanced information including actual airport names, runway and distance from airport. Displays all AI flights including passenger, cargo, military and GA.
The Fruit Stand The Fruit Stand delivers excellent, high quality AI "fruits" and repaints to the AI community. Airbus, Boeing, Bombardier and Saab.A good sense of humour makes reading their web site a bit of a treat.
Traffic 360 (was Traffic X) Information on Just Flight's Traffic 360 for FSX and Prepar3d. It features over half a million AI flight plans, over 2,400 individual aircraft variants, a host of custom utilities and innovative functionality to control and monitor your AI traffic around the globe.
TTools
Companion
TTools Companion by Bill Schroeder can quickly merge and sort flightplan, airport and aircraft files while removing duplicates. Also includes a tool to evaluate AI flightplans for errors. Find it in the file library at AvSim.
Ultimate GA The UGA team produce huge general aviation (GA) AI packages that bring your smaller airports to life, as well as AFCADs, models, textures, repaints and timetables. Forum.
Ultimate
Traffic II
Redeveloped from the ground up, Ultimate Traffic 2 provides FSX users the definitive answer to their AI Traffic needs. The project is a culmination of over three years of research and development. Forums for all versions.
World of AI An independent group of enthusiasts whose aim is to provide high quality AI traffic packages to enhance FS 2004. With just a few clicks you will have airports worldwide populated with airline, cargo, military and GA AI traffic.
yRoute AI traffic routes, airports, aircraft editor by Spacejock. A graphical front end to Lee Swordy's TrafficTools.