Greetings
I see. How does proprietary userspace code work then?
Could I help to dissolve the "sketchiness" you observed?
Many projects have used the idea of glue code as a way to link proprietary and free software together as a way 'around' the GPL, and this sounds a bit like the same thing. It's questionable if it works though.
Through magic wrapper, as usual, when one does not want to share sources but should link with open source library.
@Norman: I think many of us are needed in something like decision tree with examples, what and how we should do with source code, how to wrap own code in accordance with the license.