Benjamin M. A'Lee wrote:
They're not required to make their changes available. They're required
to acknowledge your copyright, but your licence does not require
proprietary developers to release changes at all and it does not require
GPL developers to release changes under your choice of licence.
As I understand it, if a GPL developer wants to extend a BSD licensed
file, they only have two legal choices:
- release the modified file with just the BSD license (no additional
GPL license)
- release the unmodified file and a separate GPL-licensed patch
Note that I purposely exclude two cases, because they are illegal:
- release the modified file with only GPL license
- release the modified file with BSD license and additional GPL license
The reason why the first of these is illegal should be obvious. The
reason why the second of these is illegal is because, by adding the GPL
license to the same file, it applies to the BSD-licensed text, which is
in contradiction to the BSD license. To be clear, the BSD license
allows binary distribution without source disclosure while the GPL
license does not. Thus, by adding the GPL license to a BSD licensed
file, it is taking away BSD-granted rights.
Can anyone confirm this understanding?
Regards,
Kent
