حذف یادداشت حقنشر کانتائو
by Hamid Peywasti
جمعه ۱۰ آذر ۱۳۹۱
Thanks to Tristan and Xtra from the "Extension Repository" workgroup, we have received a detailed estimation from the Free Software Foundation Europe (FSFE) regarding the question to which extent the LGPL license protects the Contao copyright notice from being altered or removed.
Limited to the LGPL
The FSFE estimation is limited to the analysis of the license terms of the LGPL. The usage of Contao is however not only subject to the LGPL license, but also e.g. the German copyright law. In addition, the license terms of the LGPL originate from the USA and do not necessarily comply with laws and regulations of other countries.
Therefore the FSFE statement cannot be understood as legal advice.
Distinction has to be made
There is no doubt that the license terms of the LGPL state that the copyright notice of the author of a work must not be altered or removed. The crucial question is what is part of the work and what is not.
The Contao back end is the graphical user interface of the CMS and thus clearly part of the work. The license terms of the LGPL apply and so the copyright notice must neither be altered nor removed. Especially the visible copyright notice on the login screen of Contao is protected by these terms and must not be deleted or hidden via CSS.
The front end of Contao, however, being the generated HTML markup of the web site made with Contao, is a separate product and not part of the work according to the FSFE. Hence the license terms of the LGPL do not apply here and there is no legal basis which could prohibit the removal of the copyright notice.
So in contrast to our previous assumption, removing the copyright notice from the source code of the generated front end web site is – at least according to the LGPL – allowed.
The purpose of the copyright notice
The invisible copyright notice in the source code of the web site helps us to make the Contao project more popular. It is targeted towards people who do not know the CMS yet.
If a company e.g. analyzes a web site, it will most likely stumble upon the Contao notice and thus find the project. It might even add Contao to its portfolio and offer it to its clients, who then get to know Contao as well. Opening up and maintaining channels which could lead to a similar result, e.g. buying ads which might reach this company, would mean a lot more effort and higher costs for us.
The copyright notice, however, neither costs us nor the web site operator anything but can have a huge effect for Contao. The manpower and money which we do not need to spend on marketing can be used to further develop Contao instead.
Elimination of the copyright notice
Of course we understand that not everyone wants a copyright notice in the markup of his web site. And we also understand that we have no right – at least according to the license terms of the LGPL – to deny you the removal of the copyright notice.
Therefore we abandon the copyright notice in the source code of the generated front end web site from now on. However, this only applies to the front end and explicitly not to the back end, which as the graphical user interface of the CMS is indisputably protected by the LGPL. To remove copyright notices in the back end or in the PHP files of Contao, you still need a commercial license.
The code which automatically adds the copyright notice will be removed in the next Contao versions (2.11.7, 3.0.1 and 3.1.beta1). Instead, we will add a meta generator tag to the "fe_page" template, which however can and may be permanently removed by adjusting the template file.
Just like the copyright notice, the meta generator tag is only visible in the source code of the web site and does not affect the web site itself in any way. With the meta generator tag, we are trying to preserve the possibility to notify people of the Contao project when they analyze a web site.
Even if there will be no automatic copyright notice in the future anymore, I still hope that many users keep supporting the project by preserving the meta generator tag or adding a back link to contao.org on the "legal notice" page or in the footer of the web site.
I would be glad if this article helps to understand our motivation and why this kind of "advertisement" is so important for Contao.