I finally made up my mind about setting up a INN newsserver. I'll admit
having been always fascinated by NNTP: it's my weak spot when it comes
to old Internet protocols.

■ About NNTP
I find NNTP very suited for any form of serious debate.
This is inherently bound to its design and perfectly coherent with its
scope. I like that sort of structured, thread-based, plain-text debate, 
with posts accurately subdivided in easily accessible hierarchies. I like
top quoting and wrapping at 78ch, the UI provided by most historical
nntp clients, the possibility to always access this sort of info from any
machine capable of connecting to the internet. The long legacy of Usenet
makes it even more charming.

I've been posting on the Usenet since I was a teen, and I'm always
surprised to see how certain groups (mainly under the comp.* hierarchy)
are still fairly active and spam-free. But those are rare exceptions
amid the ocean of spam, pirated binaries and silent and forsaken
graveyards which the Usenet has turned into nowadays. I'll post my list
of 'good' newsgroups another time.

■ Hosting a newsserver 
Since nowadays nobody seems anymore developing newsserver software, INN
appears pretty much the only viable option for anybody willing to host a
private newsserver with doesn't relay with (and pull news from) any peer.
Like other historical network servers for UNIX, INN reflects its age in
its complex and convoluted configuration, unfriendly documentation,
weird syntax and features which would be uncommon today as development
choices. That said, I've come to like it.

I had my hard time getting INN to work on NetBSD (HEAD). The deamon was
segfaulting on startup. I created a  bug report here:
<https://mail-index.netbsd.org/pkgsrc-bugs/2022/03/14/msg071095.html>

On UniteBSD, @rvp was so kind to illustrate to me that this was caused
by the compiler not finding the correct function prototype for
reallocarray() on NetBSD; I  therefore recompiled news/innd with
CPPFLAGS="-D_OPENBSD_SOURCE" and the problem was solved.

I finished configuring my previously half-baked INN server and launched
it. You can now connect to <news://retrobsd.ddns.net> at default port
119 with any client capable of speaking nntp. For the time being, the
server will only host a single newsgroup for the unitedbsd community and
those interested in *BSD. Seems kind to fit this server. More groups may
pop up, depending on the traffic (which in all due honesty I don't
expect to be high).