I love XMPP and am hopeful for its future with what the teams behind Movim[0], and Fluux[1] are doing. It was a tremendous shame that Matrix didn't improve upon XMPP and instead did their own thing. I continuously wonder what would the XMPP ecosystem look like, if the millions of dollars of funding Matrix initially had (what a waste) went to XMPP instead?
It makes sense. It's old, crufty mix of extensions, which nobody actually wants to be that modular for a chat client, because that just gets you into mess of what server/client supports
If you allow for independent implementations of the protocol this will always happen. Also, inventing another non-standard protocol creates even more incompatibility between clients and servers.
Matrix is in the same place wrt feature mismatches. It's a quality of the problem, not of the solution. I actually think XMPP does a better, more structured job here.
XMPP leans heavily on capability negotiation and service discovery which makes it straightforward to degrade gracefully when feature mismatches occur. Matrix is significantly lacking in this regard.
I strongly prefer that with XMPP I can disable the encryption when it breaks to tell my friend I'm trapped under a boulder and bleeding out. With Matrix our chat is encrypted, I can't turn it off ever, if it stops working I can't communicate, my only option is to make a new room with encryption disabled and invite my friend hoping he sees the invite and accepts in time.
Matrix is nearly as old today as XMPP was when the Matrix project was started, and Matrix is still such a pile of shit standard that there's STILL only one server implementation and one client. That's actually not how the standard was designed; if Matrix had been a successful project, according to their own goals, the ecosystem would look a lot more like XMPP than it does.
Comparing XMPP at 11 years old to Matrix today makes it abundantly clear that the main thing Element LLC does is waste European public grant funds
Also, imho Matrix is a better standard than xmpp, because of what PunchHamster said and the better feature set.
Of course, everyone is entitled to their own opinion :)
I think GP was speaking hyperbolically, because most new features hit Element/Synapse first and other clients lag behind implementing them. If you care about more than the basics working, it's kind of just the illusion of choice.
"Oh, I'm sorry, did you want it to work? You should have installed the 'it actually works' modules."
Working with XMPP gave me a whole new appreciation for why people keep inventing their own chat protocols. I don't think this is an unsalvageable situation, but the protocol is desperately in need of an "XMPP: the Good Parts" doc.
It's because the xmpp standard is absolutely brutal. I've tried to stand up a server and the amount of configuration I had to do just to get off the ground was absolute nonsense.
It's sort of the Apache of chat protocols and that's not a compliment.
> I've tried to stand up a server and the amount of configuration I had to do
I run my own server for 2 people. Using Prosody [0] took some config but wasn’t that hard. Easier than installing Arch, harder than installing Windows ;)
Nowadays, there is also Snikket [1] by the Prosody maintainer, which is essentially an opinionated all-in-one configuration setup based on Prosody, barely any config needed.
FWIW, I think I had to fight a bit to figure out setting everything up correctly for uploads to work. But as I said in sibling, nothing too problematic.
Yeah yeah yeah. I’ve heard this for 8 years. And yet, everyone can talk a great game, no one can build a mobile client that is anywhere near the quality of any other chat platform.
And here I am, hosting a Matrix server for my family for 6 years now, with no issues and an amazing experience, from the backend to the huge variety of mobile clients, a mature Rust sdk that I can hook bots into with ease, etc.
I was on Miranda. It was tiny and portable (unlike Trillian) and could connect to pretty much every popular messaging service, including IRC. And in spite of being able to connect to everything, it used far lesser memory than even just a single instance of MSN and Yahoo. It was one of my go-to apps that I'd install on a freshly formatted PC back in the day.
I have recently picked up XMPP as my agent communication layer, and its worked great. Each pi agent is given an account and wrapped in an XMPP client[0] that lets it speak to me and other agents when needed.
This has worked well since I can spin up new accounts on demand and I can use existing server software (ejabberd, perfect) and clients (Fluux, great; Conversations, okay). I've had to make a few custom modifications to each client to make agent comms a bit nicer (e.g. exposing status messages more prominently since I use that to expose current agent commands), but the XMPP layer has had pretty much everything I could have wanted.
Controlling a chat service is a bit intoxicating, I'm now using it as my notification service over a bunch of different projects.
I used Google Chat way back, its nice that the tech is still around and great as ever.
pi-msg doesn't support bonjour, I'm running it on a nixos server (nix is the real secret ingredient of my whole setup) the xmpp server is the same machine as the agents. I'm almost always on a different network to the one where the server is. If the server goes down the agents and ejabberd are coming down simultaneously.
This is really neat. I've recently been watching people use custom pi harnesses and thinking of jumping in, but I was dreaming of a way to do essentially what pi-msg does so that I could drive it remotely in a more full-featured way. Thanks for sharing.
Thanks! I had the same urge, I didn't want to be responsible for an entire GUI and communication layer but I did want to have a remotely controllable extensible harness, this was the perfect middle ground.
The benefit beyond that was having agents running on my server directly so they can do a lot of sysadmin and monitoring tasks, as well as suggesting config changes through PRs to my nix config.
Letting the agents bang their heads against the wall hunting down a config fix for a random malfunctioning piece of my homelab instead of me is by far my favorite part of the AI present.
I recently migrated from Google Voice to jmp.chat, which is a telephony/SMS/etc bridge to XMPP. I use Dino on my laptop, and Cheogram on my phone, and the experience has been quite nice and seamless. Next step is to host my own Prosody server and import my whole Google Voice history.
> Matrix reinvented the wheel as a rubber-tyred metro. On paper, it provides real benefits, such as climbing steeper inclines, which are then used to aggressively advertise and lobby local governments to buy in. But in the end, the municipality gets locked into a single vendor.
I stumble upon Matrix from time to time, but Jabber I haven't really seen anywhere in the past decade after my internet friends moved to IRC. Are there any bigger communities still using it? Back in the days Facebook Messenger was backed by it, so maybe there's still some bigger entity using it as a backbone for something?
XMPP these days often gets used as a friends-and-family style messenger (Think WhatsApp, iMessage, Signal replacement) rather than something communities would use (Discord/IRC). A lot of users of XMPP are also out of the public eye. NATO, police forces and intelligence agencies use it. The community style channels are supported though and a search engine for them can be found here: https://search.jabber.network/channels/1
XMPP is somewhat popular on the fediverse, especially the Pleroma side. If you meet people there who want to chat elsewhere, they likely are on XMPP. Also if you have a Disroot account it comes with XMPP.
XMPP is the pinnacle of chat that just works. And it is champion by default, which is kind of the point here. All other popular systems and servers went defunct; it will never be taken over by BigCo and left to rot. Here's to 25 more years!
Not my experience. I had to give up on it since it was just completely flooded with spam, and unlike mail readers that have ways to mitigate it, XMPP clients were ill prepared. Might still work if you keep your address hidden, but as chat-like alternative to a public email it just stopped working years ago.
What do you mean? You have to accept a friend request before someone can message you. It's more spam-resistant than email, not less. That said, I don't know if there's anything that prevents spamming friend requests.
And how am I going to find the valid friend requests under the hundreds of spam ones? I used it just like a chat version of public email, for bug reports and such, so I don't know who is going to message me beforehand.
You can mediate friends requests by having servers generate an invite link, you can generate QR codes your friend can scan on a side channel, ... There are ways
I think that's a symptom of the provider you chose, not the XMPP sphere itself. I've used Jabber/XMPP for just over 15 years and while I've seen plenty of bullshit going on in various highly popular MUCs (join-floods, phishing attempts and such) I've never personally been subjected to spam directed at me.
You can always send and receive messages no matter what XEPs are supported. Not that that is a problem in practice. There is a fairly well established subset of XEPs that everyone supports.
Unless you want to encrypt said messages. But I guess insecure communication beats no communication at all. (I also never had much luck with voice and video calls using XMPP.)
You can't even have a conversation between Conversations and Fluux because OMEMO is enabled by default in Conversations and there is just no OMEMO support in Fluux - despite it being actually modern one.
Gajim works but Pidgin doesn't even show "I sent you an OMEMO encrypted message but your client doesn’t seem to support that". Just like images, which is a first party in Telegram and even WhatsApp.
And of course most XMPP clients which support OMEMO only support an old version of it, which is incompatible with the new OMEMO version, currently only supported by KDE’s own client—Kaidan. That also happens to be the only desktop client I feel like I’d actually enjoy using (if only I could use it to talk with people not using Kaidan).
I regularly use IRC, XMPP, and Matrix. I think your description fits IRC better. XMPP kinda has a Plan 9 or Amiga type of vibe, cult following "ahead of its time", but never took off totally how people hoped, or didn't stay relevant at least.
I had a good technical experience using XMPP once but the community I found using it was an obscure one and I haven't come across another instance of others using it since. No matter how useful a tool is the main hurdle is adoption. This sort of retrospective is useful from an advocacy point of view.
Indeed. And on a Google-free Android phone the XMPP client Conversations can utilize its existing, permanent XMPP connection to deliver push notifications to other (mostly open-source) apps using an alternative to Google push (FCM) called UnifiedPush.
Any Android XMPP client recommendations? I tried one, then it's fork Monocle, and none of the seem to be able to handle simple notifications correctly.
I loved using XMPP and used to run my own server and even had the apps that would send notifications from my phone for different events over XMPP (forgot the name at the moment).
I'm all-in on Matrix right now and use it for my family but it's a far cry from the usability that XMPP had. I am still hopeful that Matrix can live up to its promises but perhaps XMPP will always be around if that doesn't work out. Who knows!
i set up a xmpp server a few weeks ago for agent orchestration and agent to human workflows. hadn't inatalled ejabberd in a very long time but feeling right at home.
You're right. I know at least one company used XMPP for things like customer support chat too. So maybe I have. I just mean the last time I used it intentionally was a long time ago before I was worn down futilely trying to convince friends to use it instead of locked down chat apps.
There was a point where Google and Facebook supported external clients, and then within the same year both Google and Facebook closed up to any external clients, then ultimately ditching XMPP.
I think of Matrix as a protocol + client/server suite; an open standard with official software backing it and a number of parallel implementations. When I wanted to stand up an independent server that could do most of what Discord does for communities, Matrix was the easy find. Encrypted chat, e2e support, and encrypted voice and video chat rooms with screen share.
I admit I didn't research "XMPP-based discord alternative" but maybe that says something about the ecosystem's health.
If only they had avoided XML. XML drove away a lot of people who would otherwise have been interested early on.
(I once found myself in the same meeting as two of the people who made the mistakes that meant you couldn’t just pipe stuff through an XML parser and hope it worked. I tend to speak my mind)
I love XMPP and am hopeful for its future with what the teams behind Movim[0], and Fluux[1] are doing. It was a tremendous shame that Matrix didn't improve upon XMPP and instead did their own thing. I continuously wonder what would the XMPP ecosystem look like, if the millions of dollars of funding Matrix initially had (what a waste) went to XMPP instead?
[0]: https://movim.eu/
[1]: https://github.com/processone/fluux-messenger
It makes sense. It's old, crufty mix of extensions, which nobody actually wants to be that modular for a chat client, because that just gets you into mess of what server/client supports
> mess of what server/client supports
If you allow for independent implementations of the protocol this will always happen. Also, inventing another non-standard protocol creates even more incompatibility between clients and servers.
IRC and email worked out pretty well I think.
Matrix is in the same place wrt feature mismatches. It's a quality of the problem, not of the solution. I actually think XMPP does a better, more structured job here.
XMPP leans heavily on capability negotiation and service discovery which makes it straightforward to degrade gracefully when feature mismatches occur. Matrix is significantly lacking in this regard.
Unfortunately, some of the features that can degrade are things like "the chat is actually secure."
I strongly prefer that with XMPP I can disable the encryption when it breaks to tell my friend I'm trapped under a boulder and bleeding out. With Matrix our chat is encrypted, I can't turn it off ever, if it stops working I can't communicate, my only option is to make a new room with encryption disabled and invite my friend hoping he sees the invite and accepts in time.
> Matrix is in the same place wrt feature mismatches.
not it isn't - still today there's no choice between incompatible room types or incompatible encryption algorithms and whatever else.
Matrix is nearly as old today as XMPP was when the Matrix project was started, and Matrix is still such a pile of shit standard that there's STILL only one server implementation and one client. That's actually not how the standard was designed; if Matrix had been a successful project, according to their own goals, the ecosystem would look a lot more like XMPP than it does.
Comparing XMPP at 11 years old to Matrix today makes it abundantly clear that the main thing Element LLC does is waste European public grant funds
Actually, Matrix has a series of server and client implementations.
Servers: https://matrix.org/ecosystem/servers/
Clients: https://matrix.org/ecosystem/clients/
Also, imho Matrix is a better standard than xmpp, because of what PunchHamster said and the better feature set. Of course, everyone is entitled to their own opinion :)
I think GP was speaking hyperbolically, because most new features hit Element/Synapse first and other clients lag behind implementing them. If you care about more than the basics working, it's kind of just the illusion of choice.
"Oh, I'm sorry, did you want it to work? You should have installed the 'it actually works' modules."
Working with XMPP gave me a whole new appreciation for why people keep inventing their own chat protocols. I don't think this is an unsalvageable situation, but the protocol is desperately in need of an "XMPP: the Good Parts" doc.
> the protocol is desperately in need of an "XMPP: the Good Parts" doc.
It exists! https://docs.modernxmpp.org/
XEP-0479: XMPP Compliance Suites 2023
https://xmpp.org/extensions/xep-0479.html
Daniel (the author of the linked article) was one of the people to define profiles for human chatting: https://xmpp.org/extensions/xep-0479.html
It's because the xmpp standard is absolutely brutal. I've tried to stand up a server and the amount of configuration I had to do just to get off the ground was absolute nonsense.
It's sort of the Apache of chat protocols and that's not a compliment.
> I've tried to stand up a server and the amount of configuration I had to do
I run my own server for 2 people. Using Prosody [0] took some config but wasn’t that hard. Easier than installing Arch, harder than installing Windows ;)
Nowadays, there is also Snikket [1] by the Prosody maintainer, which is essentially an opinionated all-in-one configuration setup based on Prosody, barely any config needed.
[0]: https://prosody.im/
[1]: https://snikket.org/
Counter point: I ran prosody for years and changed almost nothing to the defaults.
Just like with Apache, all you need is a sane default configuration that covers the most common use cases, and I think modern XMPP servers offer that.
FWIW, I think I had to fight a bit to figure out setting everything up correctly for uploads to work. But as I said in sibling, nothing too problematic.
Yeah yeah yeah. I’ve heard this for 8 years. And yet, everyone can talk a great game, no one can build a mobile client that is anywhere near the quality of any other chat platform.
And here I am, hosting a Matrix server for my family for 6 years now, with no issues and an amazing experience, from the backend to the huge variety of mobile clients, a mature Rust sdk that I can hook bots into with ease, etc.
It was so cool when facebook, google and others used to use xmpp, at that time I used a single IM client https://adium.im
I had amsn when msn and yahoo messenger were the place everybody I knew was at.
I was on Miranda. It was tiny and portable (unlike Trillian) and could connect to pretty much every popular messaging service, including IRC. And in spite of being able to connect to everything, it used far lesser memory than even just a single instance of MSN and Yahoo. It was one of my go-to apps that I'd install on a freshly formatted PC back in the day.
This used to be one of the biggest Mac open source projects. I remember they demoed project builder (before Xcode) compiling it
Best chat client ever. Man we had it good back then.
I have recently picked up XMPP as my agent communication layer, and its worked great. Each pi agent is given an account and wrapped in an XMPP client[0] that lets it speak to me and other agents when needed.
This has worked well since I can spin up new accounts on demand and I can use existing server software (ejabberd, perfect) and clients (Fluux, great; Conversations, okay). I've had to make a few custom modifications to each client to make agent comms a bit nicer (e.g. exposing status messages more prominently since I use that to expose current agent commands), but the XMPP layer has had pretty much everything I could have wanted.
Controlling a chat service is a bit intoxicating, I'm now using it as my notification service over a bunch of different projects.
I used Google Chat way back, its nice that the tech is still around and great as ever.
[0]: https://github.com/zachpmanson/pi-msg
Amazing! Perhaps my project here would interest you. Also do you have bonjour support?
https://github.com/gatlin/pii
Pii is interesting!
pi-msg doesn't support bonjour, I'm running it on a nixos server (nix is the real secret ingredient of my whole setup) the xmpp server is the same machine as the agents. I'm almost always on a different network to the one where the server is. If the server goes down the agents and ejabberd are coming down simultaneously.
Cool use case with the agents, hadn't thought of that
This is really neat. I've recently been watching people use custom pi harnesses and thinking of jumping in, but I was dreaming of a way to do essentially what pi-msg does so that I could drive it remotely in a more full-featured way. Thanks for sharing.
Thanks! I had the same urge, I didn't want to be responsible for an entire GUI and communication layer but I did want to have a remotely controllable extensible harness, this was the perfect middle ground.
The benefit beyond that was having agents running on my server directly so they can do a lot of sysadmin and monitoring tasks, as well as suggesting config changes through PRs to my nix config.
Letting the agents bang their heads against the wall hunting down a config fix for a random malfunctioning piece of my homelab instead of me is by far my favorite part of the AI present.
I recently migrated from Google Voice to jmp.chat, which is a telephony/SMS/etc bridge to XMPP. I use Dino on my laptop, and Cheogram on my phone, and the experience has been quite nice and seamless. Next step is to host my own Prosody server and import my whole Google Voice history.
> Matrix reinvented the wheel as a rubber-tyred metro. On paper, it provides real benefits, such as climbing steeper inclines, which are then used to aggressively advertise and lobby local governments to buy in. But in the end, the municipality gets locked into a single vendor.
I stumble upon Matrix from time to time, but Jabber I haven't really seen anywhere in the past decade after my internet friends moved to IRC. Are there any bigger communities still using it? Back in the days Facebook Messenger was backed by it, so maybe there's still some bigger entity using it as a backbone for something?
XMPP these days often gets used as a friends-and-family style messenger (Think WhatsApp, iMessage, Signal replacement) rather than something communities would use (Discord/IRC). A lot of users of XMPP are also out of the public eye. NATO, police forces and intelligence agencies use it. The community style channels are supported though and a search engine for them can be found here: https://search.jabber.network/channels/1
Yeah, I use it as a messenger for my wife and I.
Jitsi Meet still runs on XMPP, Prosody handles the signaling. WhatsApp also started life as a patched ejabberd.
WhatsApp is still based on XMPP unless things have changed a lot recently.
I don't consider WA a product. I don't consider it a viable product. Post-2014/Zuckerberg. Who cares if it's XMPP, it didn't federate
What about their signal integration? https://signal.org/blog/whatsapp-complete/
XMPP is somewhat popular on the fediverse, especially the Pleroma side. If you meet people there who want to chat elsewhere, they likely are on XMPP. Also if you have a Disroot account it comes with XMPP.
XMPP is the pinnacle of chat that just works. And it is champion by default, which is kind of the point here. All other popular systems and servers went defunct; it will never be taken over by BigCo and left to rot. Here's to 25 more years!
> XMPP is the pinnacle of chat that just works.
Not my experience. I had to give up on it since it was just completely flooded with spam, and unlike mail readers that have ways to mitigate it, XMPP clients were ill prepared. Might still work if you keep your address hidden, but as chat-like alternative to a public email it just stopped working years ago.
What do you mean? You have to accept a friend request before someone can message you. It's more spam-resistant than email, not less. That said, I don't know if there's anything that prevents spamming friend requests.
And how am I going to find the valid friend requests under the hundreds of spam ones? I used it just like a chat version of public email, for bug reports and such, so I don't know who is going to message me beforehand.
Fair enough. I've only ever used XMPP when Google chat used it and at work in the days before Slack.
You can mediate friends requests by having servers generate an invite link, you can generate QR codes your friend can scan on a side channel, ... There are ways
Or you can just show the welcome message from a new contact, just like anyone else does. Adding a 2nd factor here is the reason XMPP suck.
I think that's a symptom of the provider you chose, not the XMPP sphere itself. I've used Jabber/XMPP for just over 15 years and while I've seen plenty of bullshit going on in various highly popular MUCs (join-floods, phishing attempts and such) I've never personally been subjected to spam directed at me.
I have joined XMPP rooms via Matrix and have already gotten spam from XMPP this way
Which is surprising since XMPP allows you to hide your global address in public rooms and Matrix doesn't (unless they fixed it by now?).
> XMPP is the pinnacle of chat that just works.
No. It doesn't "just work". It very much depends on which subset of the XEPs all the parties in the chain support.
> All other popular systems and servers went defunct;
Well, in this sense it does just work :)
You can always send and receive messages no matter what XEPs are supported. Not that that is a problem in practice. There is a fairly well established subset of XEPs that everyone supports.
https://xmpp.org/extensions/xep-0479.html
https://compliance.conversations.im/
Unless you want to encrypt said messages. But I guess insecure communication beats no communication at all. (I also never had much luck with voice and video calls using XMPP.)
> XMPP is the pinnacle of chat that just works.
Except no.
You can't even have a conversation between Conversations and Fluux because OMEMO is enabled by default in Conversations and there is just no OMEMO support in Fluux - despite it being actually modern one.
Gajim works but Pidgin doesn't even show "I sent you an OMEMO encrypted message but your client doesn’t seem to support that". Just like images, which is a first party in Telegram and even WhatsApp.
So much for 'just works'.
And of course most XMPP clients which support OMEMO only support an old version of it, which is incompatible with the new OMEMO version, currently only supported by KDE’s own client—Kaidan. That also happens to be the only desktop client I feel like I’d actually enjoy using (if only I could use it to talk with people not using Kaidan).
I regularly use IRC, XMPP, and Matrix. I think your description fits IRC better. XMPP kinda has a Plan 9 or Amiga type of vibe, cult following "ahead of its time", but never took off totally how people hoped, or didn't stay relevant at least.
We use xmpp for our company’s IOT product suite. Works quite well with its presence and messaging capabilities .. Backend runs ejabberd.
When I ever have time...
1. Gain/find-someone-with crypto library use knowledge.
2. Jabber client with Iroh networking and E2EE.
3. Completely remove XMPP server dependence.
4. Allow users to exchange Iroh-Node-ID outside of jabber (QR code, other secure channels?), store in Jabber contacts.
5. Develop from there. Calendar usage, multiparty, backups.
But I have neither the time nor the knowhow right now.
I had a good technical experience using XMPP once but the community I found using it was an obscure one and I haven't come across another instance of others using it since. No matter how useful a tool is the main hurdle is adoption. This sort of retrospective is useful from an advocacy point of view.
I think Android still uses XMPP to delivery push notifications under the hood
Indeed. And on a Google-free Android phone the XMPP client Conversations can utilize its existing, permanent XMPP connection to deliver push notifications to other (mostly open-source) apps using an alternative to Google push (FCM) called UnifiedPush.
There was a talk at FOSDEM about that.
https://gultsch.video/w/gRGZqKKvNBvvMesyWNQzoK
Unless I'm mistaken, Apple's push notifications network ("APN") and a few other macOS/iOS under-the-hood things are also built on top of XMPP.
XMPP always seemed great, buy I have yet to find a client that can replace Telegram's client on both desktop and mobile.
Any Android XMPP client recommendations? I tried one, then it's fork Monocle, and none of the seem to be able to handle simple notifications correctly.
Never had notifications issues with conversations.
Seconding Conversations, though I wish it'd let me disable relative timestamps.
I loved using XMPP and used to run my own server and even had the apps that would send notifications from my phone for different events over XMPP (forgot the name at the moment).
I'm all-in on Matrix right now and use it for my family but it's a far cry from the usability that XMPP had. I am still hopeful that Matrix can live up to its promises but perhaps XMPP will always be around if that doesn't work out. Who knows!
MAXS? As far as I can tell, it is broken by newer versions of Android.
Its biggest issue is adoption because it's very solid otherwise and even supports stuff like screen sharing.
screensharing is ubiquitous at this point
i set up a xmpp server a few weeks ago for agent orchestration and agent to human workflows. hadn't inatalled ejabberd in a very long time but feeling right at home.
And I haven't used XMPP for about 20 of them (sadly)
There was a time where both Google Chat (whatever it was called back then I lost track) and Facebook Chat were built on it. So you might have.
You're right. I know at least one company used XMPP for things like customer support chat too. So maybe I have. I just mean the last time I used it intentionally was a long time ago before I was worn down futilely trying to convince friends to use it instead of locked down chat apps.
That's fair, no worries.
Google Talk - and it was an actual federating XMPP server, in contrast to Facebook which merely allowed you to login with an XMPP client.
There was a point where Google and Facebook supported external clients, and then within the same year both Google and Facebook closed up to any external clients, then ultimately ditching XMPP.
25 years of independence and, dare I say, irrelevance.
I think of Matrix as a protocol + client/server suite; an open standard with official software backing it and a number of parallel implementations. When I wanted to stand up an independent server that could do most of what Discord does for communities, Matrix was the easy find. Encrypted chat, e2e support, and encrypted voice and video chat rooms with screen share.
I admit I didn't research "XMPP-based discord alternative" but maybe that says something about the ecosystem's health.
My first task at my first real tech job was setting up an ejabberd server
If only they had avoided XML. XML drove away a lot of people who would otherwise have been interested early on.
(I once found myself in the same meeting as two of the people who made the mistakes that meant you couldn’t just pipe stuff through an XML parser and hope it worked. I tend to speak my mind)