I wonder what extensions are recommended atm if you need comments or a forum.
On Structured Discussions I read that the project ended in November 2023 and everyone is advised to archive their discussion (what the?). Is there a follow-up? On the other hand this very support desk uses exactly this?
What should I use if I start a wiki nowaydays and want future-proof comments under article pages instead of talk pages?
Structured discussion is dead, I wouldn't use it. I'd argue it is impossible to maintain for 3rd parties, with a lot of exceptions and interventions that differ from how we do things in MW.
Everything Wikimedia will eventually switch to using DiscussionTools.
I have a much better feeling about discussion tools than flow. Its already been fairly well recieved by the community, where flow was controversial right out of the gate. I think it has staying power (just my 2 cents, i dont have access to a crystal ball any more than anybody else)
@Subfader: Out of general curiosity, exactly what is the problem with Comments? As the maintainer and primary developer of it since 2011, I'd be curious to know. :) Its User Interface is pretty stable and definitely not using the latest fancy design things, but it gets the job done. (I'll admit, though, that OOUI did end up lasting for several years longer than it did, but that, too, is being phased out and I'm sure that the successor will also be sunset in favor of a newer, shinier gadget, give it some time. Not using these sort of frameworks comes with the unexpected benefit of your code working regardless, if you can tolerate a somewhat "dated" looking UI.)
For the record: the initial version was written circa 2006 (!) and as it (like other social tools originating from ArmchairGM which enable new content types, like Extension:FanBoxes, Extension:LinkFilter, Extension:Video, ...) predates MediaWiki's ContentHandler system by many years, it does things in a way which isn't ideal, yet it's surprisingly functional and shockingly robust (in my biased opinion), because even major core changes aren't likely to disrupt this little extension which does things in its own way.
Some people argue that "no recent code commits" (or something similar) equals to a dead project. I largely disagree; while it may mean that the end-user should exercise a bit of caution and carefully test things etc., not all MediaWiki developers are huge fans of "move fast and break stuff", which, alas, seems to be all too common these days. Sure, it bumps up a repository's commit count a lot, but what for, and at what cost?
Now, as for Comments' actual architectural shortcomings...while the comments are associated with a(n existing wiki) page, they are indeed in other ways separate, they are not regular wiki page content or anything. So implementing a history interface (phab:T156736) or the ability to undelete previously deleted comments (phab:T127595) is very tricky, to say the least, and I for one would be very surprised (but in a positive way!) to see those implemented before Comments turns 20 years old in 2026.
Sorry, not old as outdated code but interface-wise. From the screenshots it looks like forum discussions from early 2000s.
Do you know of sites that use it which you could link or mail me?
In over 15 years I went from ArticleComments to some forum extension I forget and then Flow. Each time I was forced to throw away all old comments and posts. Not funny when you try to run a community. This timed I prefer some more LTS.
CSS wizards can probably suggest tweaks to the existing styles to make 'em more modern. I'm not enough of a CSS guru nor "modern" to know, though. :) The look hasn't bothered me and nobody's submitted a patch to improve things, so alas. As always, patches are more than welcome (but as a volunteer I cannot guarantee that they would definitely be tested/reviewed in a given time, or merged)!
Comments is one of those social tools extensions which doesn't even require SocialProfile and it's a pretty popular, basic functionality, so I'd expect plenty of sites out there to use it. (If only WikiApiary was a bit more stable...) Here's an example page on Brickipedia, the LEGO encyclopedia hosted by ShoutWiki, which uses comments.
Ah, ArticleComments...I remember that. It's been a while, eh? Out of sheer curiosity I did some digging, dug up the MW 1.20-compatible version and tried getting it working. It wasn't even that difficult, although it's still not working perfectly for me locally. The code somewhat shows its age, although admittedly its brilliance is that the "comments" are indeed just regular wiki edits on a regular wiki page. For example, the PostComment extension by wikiHow took a similar approach.
Flow was always dead-on-arrival software, but the problem was that you couldn't say it out loud that the Emperor has no clothes. I'm sorry you ended up wasting your time with it. The WMF has a rather poor track record with discussion-related extensions, although Extension:DiscussionTools is doing better than Flow ever did and it has been more positively received by the various communities on WMF web properties.
Migrations absolutely are horrible to do, and it's oftentimes just uncharted territory, and basically always so with MediaWiki extensions (e.g. "how do I migrate from extension X to Y or Z?"). There are various reasons as to why, but I think the main ones are technical complexity and a ridiculously small target audience, plus probably funding or the lack of thereof.
Predicting the future is, of course, impossible. There are many reasons why some of the social tools are kinda horrible, as I explained in my earlier response; and yet, bizarrely enough, these same reasons might also be why they're surprisingly great (in my biased opinion, of course). Comments and others precede ContentHandler by several years, and while this has rather obvious drawbacks, it also means that these extensions have stayed surprisingly stable over the years (or decades, I should say, for a lot of them will be turning 20 years old in ~2-3 years (!)) by not relying on the standard MediaWiki way to do things. Whether this is or isn't something you want is a question only you (and your community) can answer.
Also, I should point out that there are probably some other, likely even better commenting/discussion-related extensions. I just happen to be most familiar with the extension that I maintain.