I installed with 'apt install ejabberd'
I followed the docs pointed to at the top of /etc/ejabberd/ejabberd.yml, which pointed off to old blog posts for some things (unaccepable).
I configured /etc/ejabberd/ejabberd.yml to edit hosts, acl. acme, and certificates as best I could from those old blog posts.
I copied certificates from letsencrypt into /etc/ejabberd and made them owned by ejabberd, pointed to by the yml file.
I added my host to /etc/hosts (stack overflow solution)
And yet running "systemctl start ejabberd.service" or "systemctl stop ejabberd.service" simply hangs without giving me my shell back.
That is unacceptable. Broken piece of shit. 

 Iirc, ejabberd does something wacky with the certificates including the root certificates by copying them into /var somewhere. I gave up on xmpp about 5 years ago. Moved to an interim solution, then changed over to matrix. I can see an eventual element clone coming built on nostr. 0xChat is getting close, but one needs compatible desktop and browser clients. Element.io is an amazing utility. 

 Matrix is Israeli spy software. It's also bloatware. 

 Are you serious? 

 Https://lukesmith.xyz/articles/matrix-vs-xmpp/ 

 I could never get voice and video to work with my xmpp server. Maybe its worth another try. Of course I would never do something ao retarded as use the central matrix server, but I always wondered about their directory service so I turned it off. No doubt their pwa still leaks data even if you always use a "homeserver", but the main feature I'm not willing to give up is video, screenshare and voice calls. If you were in charge of a development team and the tools they use, how would you solve this problem given that e2e MUCs witg omemo are a central component of your use-case? 

 I don't know.  I'm not personally interested in voice and video.  I just want to get group chat off of Telegram. 

 I know there is the jingle protocol (sip over xmpp) but i never got it to work and i'd want a desktop client that can also screenshare 

 @Mike Dilger @Low Information Voter Hello, dear Mike!

The easiest to use clients are Cheogram on Android and Gajim or Dino on Linux.

Regarding the servers, you can join any one.  I like jabber.fr

If you want to run your own server, I heard the easiest is with Snikket. I know people who even set this up for their family.

The link is:
https://snikket.org/start/

You could pay for the people there to just make it work for your, or self host here:
https://snikket.org/service/quickstart/

For what I understood, Snikket is a pre-configured version of one of the famous servers (dont remember which now)

If you need the direct link to its docker file, its here:

curl -o docker-compose.yml https://snikket.org/service/resources/docker-compose.yml 

 I got prosody to work, and Gajim.  Thanks. 

 Yeeeaaahhhhh!!! Party!!!! 

 This is how you send an XMPP chatroom link (in this case the room of prosody users):

xmpp:prosody@conference.prosody.im?join 

 On Signal you relay on the Signal company, which can change their policy at any time.

Simplex also you rely on one app only.

XMPP is distributed, meaning any Mr. Random can open a server and a client, and thus you are not locked in