A company X which creates a product A, has decided to dual-license their
project under the GPL and a commercial-license. They have asked not to
publicise this until the official release which is why I am using
generic terms - i.e. this is a real question with immediate relevance,
and not a hypothetical one.
They want the source tree to be the same for both editions -- the Open
Source Edition and the Professional Edition. They have called for help
in rewriting the license declaration in their source files. I have
crafted the attached license declaration for this purpose.
Please check and say whether:
1. the license declaration is sufficient for the desired purpose or it
is lacking in any way
2. the license declaration does not conflict with the GPL
3. the license declaration contains anything superfluous which is
already mentioned by the GPL
4. the product so licensed is DFSG-free -- i.e. product A may be
packaged for Debian