Google Calling: Inside Android, the gPhone SDK (O'ReillyNet)

It's not a case, but djb's oft-expressed opinion that anyone has the right to release a patch
to his software guaranteed to them by copyright law, without any further intervention from
him, is applicable here too. As far as I am aware, the licensing problems with qmail do not
stem from that - otherwise, netqmail would be in trouble.

In any case, as far as I'm aware, nVIDIA do it the way they do for technical reasons - it
means they don't have to support a different binary module for every single kernel version out
there, instead relying on their thunk to be recompiled for the particular kernel under which
it finds itself installed. It might also make redistribution of the driver with a precompiled
kernel permissible - strictly speaking, the closed-source part is not derived from Linux; only
the thunk is, and that is GPL'd - but that's one for lawyers.