Can I include GPLv3 licensed documentation in a collection of GFDL licensed documents, or: what are the limits of an "Aggregate" in GFDLv1.3/GPLv3?

Question

This is a follow-up question to a question concerning the meaning of "Modified Version" in the GFDL

Context: I have created a website which hosts a collection of (as concluded in the previous question) modified versions of GFDL documents. I (and others) would like to possibly include other manuals there as well, some of which are licensed under the GPLv3.

How, if at all, is this possible without the express consent of the GLPed manual's copyright holder(s)? In order to display the text on the website, I need to convert the original source code to Markdown, creating a "Modified Source Version" as per section 5 of the GPLv3, which means I am required to "license the entire work, as a whole, under this License to anyone who comes into possession of a copy".

I feel like this comes down to whether my website constitutes an "aggregate" in the sense of the GPLv3 (Section 5) or the GFDLv1.3 (section 7) or a "Collection" in the sense of the GFDLv3 (Section 6).

In the GPLv3 sense of "aggregate", they do somewhat "combine to form a larger program"(GPLv3 Section 5) namely the set of manuals/website called "Emacs Docs", however they are somewhat independent, as when we interpret "source code" in the GPLv3 to mean "The Manual", the works do not per se form a larger "Manual" together, as the website simply provides access to the modified versions of said manuals without claiming to be one cohesive manual.

If the website does not count as an Aggregate, I am required to license it under either the GFDLv1.3 or the GPLv3, which would include either relicensing GFDLv1.3 manuals as GPLv3 or vice-versa, both of which do not seem possible given the limitations the GFDL places on modification (invariant sections).

It seems then that my only option (if my website does not constitute an aggregate) would be to dual-license it under GFDL and GPL, which seems like a hassle I would not like to deal with.

Answer 1

It is pretty clear that your website, which puts different manuals side by side (and does not merger the manuals into one larger document) is an aggregate.

The GPL FAQ are pretty clear that what you are planning to do would be OK if it was put on a CD-ROM. Your website is not much different in terms of making things available, so what is OK for a CD-ROM or other media will also count for your distribution on a website.

W.r.t. GFDL there seems to be something like a definition for 'Collection' in Section 6 "You may make a collection consisting of the Document and other documents released under this License..." which I am interpreting that a collection can only apply if all the documents that are combined are under the same license. As this is not the case, according to your description, your website will be an Aggregation under the terms of GFDL. (Unfortunately the FDL FAQ is not very helpful for this question.)

You may have your website itself under any license as long as you do not restrict anyone from exercising their rights based on the licenses of the documents you are incorporating. So as an example your website ('HTML') might be under the Apache License and you may use 3rd party JavaScript with compatible licenses, while the documents themselves remain under the licenses provided by the original authors (GPL or GFDL as the case may be).