Does the license only apply to those to whom the binary has been distributed
to? If the plugin is never publicly released, does the license imply that
only the receivers of the plugin are required to be sent the source code?
If the plugin is never seen by the public eye, does that imply that the
source code may stay private as well?
[NPP>] IANAL, but I believe that if you ship a modified binary to a third party, you must ship it and the source code (or a promise to make the source
code available) under the same GPL license terms as the original. You cannot oblige the third party in any other way from using that code except for the GPL. That means you cannot control whether the third party chooses to keep both the source and binary private,
or whether they choose to make both public – that becomes their decision, not yours. Further of course the third party can only pass the software on under the same GPL terms, including the source.
Neil
