Firstly, TINLA, and brace yourself.
On 1/18/07, Mark Clements gmane@kennel17.co.uk wrote:
This pops up every so often at www.mediawiki.org, particularly in relation to the public domain help pages that we are trying to compile.
What is the correct license for screenshots of MediaWiki? Are we able to distribute them along with the PD help pages (when we get to that stage)? Currently they are variously tagged as GFDL, PD, (c) WMF and possibly others.
The simple answer is that MediaWiki is GPL, so screenshots of a plain old MediaWiki install, with no other things in it, are GPL.
Are there any considerations that may cause some screenshots to be under one license and some under another? E.g. if the screenshot includes the MW logo or certain interface text does it affect how it can be licensed? What about the different skins?
When you start mixing stuff you complicate things. If I were to take a screenshot of a page on Wikipedia, for example, the text of the page would be GFDL (unless there are some quotes or something in the text, which would be fair use), the MediaWiki elements would be GPL, the browser window could be anything (if you're in Firefox, for example, then the picture of the browser interface is under the Mozilla Public Licence). The skins that come with MediaWiki are GPL just like the rest of MediaWiki.
So unfortunately you can't get PD screenshots of MediaWiki. The best you can do is GPL screenshots, but only if you show only GPL content in it and either cut out the browser interface or use a GPL browser. You could also create a screenshot with the MediaWiki interface and some other free content in it (like Wikipedia content) and the result would be that there would be different licences for different parts of the picture.
The last point is the logos. The Wikipedia logo, among others, is not under a free licence so you really can't show that in a screenshot if you want the image to be freely licenced. The MediaWiki logo, IIRC, still has a fairly iffy copyright status, noone seems to know whether it is PD or GPL. But that may have been resolved since the last time I read about it.
Lastly, here's a few examples:
http://commons.wikimedia.org/wiki/Image:Accueil-Safari-Alibaba.png French WP in Safari. The Safari elements are LGPL, MediaWiki elements are GPL and the WP content is GFDL.
http://commons.wikimedia.org/wiki/Image:Aide_FR_Metadata_image.png Only shows MediaWiki elements, entirely GPL (the metadata shown is probably not eligible for copyright).