The package FMUGeneration works for me now (see here). Follow-up questions:
Is an FMU file always OS specific? Do I need three of them if I want to support Windows, Mac, and Linux?
Does the user of an FMU need to have Julia installed?
Does the creation of FMUs work on Mac and Windows?
Can I create FMUs for Windows on Linux?
I have a free, academic license of Dyad. Am I allowed to distribute FMUs to my students? If yes, under which license?
To answer my first question: I think in the context of Julia the answer is (currently) yes, because an OS independent FMU must contain only C source code and no (compiled) shared libraries. In theory, an FMU could also contain shared libraries for multiple OS, though.
Well, my interpretation is, that if you create an FMU and distribute the FMU, you are not distributing Dyad. You are just distributing the output of a compiler.
And yes, it would be nice if the license for the output of the compiler (which will include some shared libraries) were clearer. But for me, it is clear enough, if the output is used for educational purposes, I am allowed to distribute the FMUs.
I might ask the advisor of our University if that is clear enough, or if we need further clarification from JuliaHub.