The EUPL is a fine license, especially if your goal is wide compatibility with other copyleft licenses. However, that compatibility also weakens its own copyleft, which could be surprising if you just read the main text.
Also, the GPL is not as short and has more explicit wording for how it behaves in common situations (like the P2P copying stuff, for example), and it allows certain additional restrictions and exceptions (like what the LGPL is). It's just more well thought-out in my opinion.
Edit: Reading it again, I also just remembered that the EUPL's warranty disclaimer is a lot weaker than usual licenses, and weirdly also asserts the program is a “work in progress”.
> However, that compatibility also weakens its own copyleft
Keep in mind that within EU the GPL's copyleft is as strong as EUPL's or LGPL while at the same time EUPL takes into account network access like AGPL. In practice though, software is distributed outside of the EU and while GPL relies on local laws to "maximize" its copyleftness, EUPL specifically refers to either the EU country of the developer or Belgium if the developers from outside the EU, where the laws do not distinguish between static or dynamic linking (check "More details on the case of linking" from [0] about license compatibility). Also FWIW while FSF suggests that "license hopping" (i.e. changing to some compatible licenses from EUPL to something else) weakens the copyleft, a European Commision lawyer who worked on EUPL has commented doing so would be copyright infringement because the purpose of the compatibility list in EUPL is for interoperability (so that multiple projects with different licenses can coexist) and the purpose would matter in court.
Though in practice since software is often distributed outside of EU, e.g. to US where (it seems) such distinction does exist, people do respect (L)GPL's dynamic vs static linking requirements and from a worldwide perspective EUPL is something like LGPL with a dash of AGPL (making some program functionality available even remotely is considered as distribution). Or in other words, EUPL is basically AGPL within the limitations of EU law.
That depends on your interpretation of what a “derivative work” constitutes, which the EUPL delegates to copyright law. For the GPL, it includes other programs linked to the work (which is how it affects other projects using the work as a library). If this definition held true for the EUPL as well, it would behave the same way. (By the way, I don't really like describing copyleft as “viral”, because that implies the GPL (and similar licenses) are like infectious diseases.)
However, the compatibility clause allows relicensing to other licenses that are explicitly weaker in their copyleft, which is what I meant with the quoted sentence.
Another comment just made me aware though that apparently, copyleft extending to other programs linking with the work is just not a thing in the EU? I'll have to read more into the details of that.
It hasn't failed. Not if you do what crowdsourcing requires and suggest a better replacement.
I agree that "Solving 2D geometry puzzles using 3D reasoning" does not fit the actual topic of the video, so I have replaced it with "Geometry puzzles with 4D analogies" for now – which is also not quite right, since the largest part of the video doesn't refer to any 4D concepts. I think it's, more generally, about puzzles that can be more easily solved by considering any other dimension, but it's harder to make a good title out of that.
Do you have another idea for an improvement?
Vandalism on Fandom wikis is counter-productive. It just makes it look more active, to both users and search engines, and so will in turn make it harder for people to find the independent wiki. The best thing to do is just to ignore abandoned Fandom wikis entirely.
I highly doubt that the FSF, who developed the GPL licenses and values free software above anything else, would change the licensing of their projects like "these companies" do.
> Math B seems, in contrast, beyond me. There is a programming analogy: Math B is like Haskell, or pure functional programming, which also is as ungraspable to me.
This is not just an analogy – Haskell (or pure functional programming in general) is a lot closer to math than other ways of programming. Specifically, it is derived from category theory (which fits to your description of math B being things ending in "theory" as well).
What do you mean? Does Fandom use MediaWiki? I remember them having their own independent website. Maybe I'm thinking of the MC Fandom wiki before the theme changed. It used to look exactly like Wikipedia.
Also, the GPL is not as short and has more explicit wording for how it behaves in common situations (like the P2P copying stuff, for example), and it allows certain additional restrictions and exceptions (like what the LGPL is). It's just more well thought-out in my opinion.
Edit: Reading it again, I also just remembered that the EUPL's warranty disclaimer is a lot weaker than usual licenses, and weirdly also asserts the program is a “work in progress”.