CMS

What forum engines are relevant at the moment?

They set me the task of attaching the good old forum to the subdomain of the site. The last time I did this was a long time ago.
Since then, I suspect, PhpBB, FastBB and vBulletin have moved in and made way for some new forum engines.
Who uses what, what is now stylishly fashionable, youthful?
PS I suspect that such a format of a forum on a separate engine is now quite archaic, because many discussions have moved to social networks, many forums are implemented as plugins for CMS. But it is a separate forum engine that is of interest, with moderation, captcha, topic groups, etc.