MSFS Toolkit is dual-licensed: free for non-commercial use, but requires a paid license to exploit it commercially.
I have recently discovered many examples of commercial products that have been created using the free version of MSFS Toolkit.
By doing so, they consume fruits of the freeware scene, but do not contribute back in any form - not by releasing their products as freeware, and not by acquiring a commercial license that lets me keep things free for you.
The most notable offenders are Aerosoft (Anchorage, Gran Canaria, possibly more) and Island Creations (their entire portfolio). Since I always kept tweaking processing algorithms to find good default values, I can not only prove that they used MSFS Toolkit, but also pinpoint specific versions that they relied upon.
Attempts to establish contact with them to license MSFS Toolkit retrospectively were not answered and I am now handing the matter over to a law firm to take legal action against them for software piracy.
MSFS Toolkit will be available to the public again when this gets settled.