Prosody or Snikket. But I develop both so might be biased 🙃
Happy to answer any questions though.
@Twelve Both Prosody and ejabberd (and others such as Tigase, Openfire) are generally up to date with modern XMPP protocol requirements, so you don't have anything to worry about there.
People tend to prefer one or another due to things like: ease of setup, resource usage, scalability, possibilities for customization.
@Twelve Prosody has a focus on being lightweight and very flexible. It has a plugin-based architecture so is *extremely* customizable (we have an active community and over 350 community modules at https://modules.prosody.im/ !). One of the main complaints people have about Prosody is that some important functionality is still in community modules and not bundled with Prosody out of the box, but we're working on that. A good setup guide is: https://homebrewserver.club/configuring-a-modern-xmpp-server.html
@Twelve Snikket is another solution I develop which is actually based on Prosody. It is designed to be a great starting server with everything you need set up and working out of the box (e.g. it bundles the software you need for audio/video calls to work, and it handles certificates for you automatically). Unlike Prosody it is designed with very *little* flexibility, to keep things as simple as possible.
It also has some matching apps (well, currently an Android one... an iOS one is coming Very Soon™).
Jitsi Meet's setup guide actually installs Prosody by default. However Jitsi has some specific configuration requirements (as in, it requires Prosody to be configured just how it likes), so you're best seeking Jitsi advice from the Jitsi docs.
@Twelve I've never tried it myself (I self-host Jitsi Meet, but not on my main Prosody server). I've heard people say "it can't be done", but I actually don't see why not, as long you keep them on separate domains (Jitsi vs. normal IM). Same Prosody instance should be fine, in theory...
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