I've signed an agreement with Amiga Inc which allows them to use my WHDload slaves for their game packs.
Also Bert has made a special WHDLoad version for the system.
The whole thing is wrapped and blackboxed so we don't see whdload acting in the background.
In exchange, I'm entitled to as many games as there are slaves from me which are used in the whole game library. Since my work is freeware, I don't mind.
They add to enhance WinUAE to fit their needs, but could not modify it because of the GPL license (or they would have to give away their code). I guess they hacked around it to avoid legal issues.