Please eventually see, this topic start on simplemachines.org:http://www.simplemachines.org/community/index.php?topic=461355.msg3222313#msg3222313
The problem I would like to bring to your attention is basically this:
Downloading XMas for 2.0, I find index.template.php is licensed under BSD 3-clause, as specified by the same header SMF (2.0+) original files have.
* Simple Machines Forum (SMF)
* @package SMF
* @author Simple Machines
* @copyright 2011 Simple Machines
* @license http://www.simplemachines.org/about/smf/license.php BSD
* @version 2.0
There is no other license in the package, that I can see.
In my understanding, that means that: (allow me to take it point by point, in the hope that it will be easier to discuss each as suited)
1) the PHP files code, specified under BSD, is under BSD. The entire code in the file, is declared under BSD. That means the license allows free use, modification, and distribution, in modified form or not, as long as the conditions of BSD are respected. (namely, the header is preserved).
2) the copyright of that code is declared to belong to Simple Machines, which is not entirely true, copyright for the customization work obviously belongs to the author. It is the choice of the designers/developers, of course, to specify their copyright in the source file too, or not specify it, I'm just bringing the point to your attention.
3) the rest of the design (images, css files, etc) doesn't seem to have a license specified, that I can see. Which means anyone who receives it, will have in practice no rights, unless the copyright holder gives it explicitly to them.
The main point I'd have to submit to your attention, is that this understanding is at odds on at least one aspect, with what I understand from ARG in the linked topic. In other words, according to the license, I can take the PHP file (index.template.php), modify it, and release it freely, without requiring written agreement from Dziner, since Dziner has released it giving everyone the rights by the BSD 3-clause license.
Thank you for correcting my understanding, if that is wrong.