Arno Gerretsen's Flightsim Tools

... the place where I learned that there is more to Microsoft's Flight Simulator than just flying.

FSDeveloper is by far the most friendly and competent place and community if you want to dive into the mysterious undergrounds of Flight Simulator. If you come here as a complete newbie, you will be treated very friendly, and you will find a lot of help.

Arno Gerretsen, who runs the FSDeveloper site, has published some extraordinary and unique tools there. All of them have their own support forum. Click on the images to open the wiki tutorial for each program.

ModelConverterX - FS9/FSX

ModelConverterX converts model files from different sources. Objects designed for Scasm (API, SCM and SCA) can be imported as well as certain FS9 and FSX objects. A good reason to convert old objects is to get better performance.

It also supports the conversion of animated objects and has unique features like pseudo automatic LOD creation. It is still under heavy development.

Download ModelConverterX

Library Creator XML - FS9/FSX

In Flight Simulator, a library is a file (BGL) that contains scenery objects. Library Creator XML is a graphical interface for creating libraries, allowing you to easily add, update and delete model files.

After you have assembled all the objects, the tool will generate the XML code and compile the BGL file.

Download Library Creator XML

ActiGate - FS9

With ActiGate you can access Flight Simulator variables that are normally not available. The module reads information from memory via FSUIPC. Examples of available variables:

Aircraft type used by the user If the parking brake is set or not If it is raining or snowing The day of the week
Download ActiGate

CAT - FS9

Conditional Animation Tool allows you to attach conditions to your GMax animations. For example, you might want a hangar to open only when you approach the door instead of running endlessly.

Download CAT

MDLTweaker-II - FS9

With MDL Tweaker you can tweak scenery objects (mdl files) without modifying the ASM source code. Supported tweaks include:

Rotation to the user Rotation with the wind Display depending on specific condition
Download MDLTweaker-II
This page was last modified on Monday, 06 April 2026 - 09:26