Sure, now which pre-existing piece of xmpp based software checks all the feature boxes as noted by both Signal adherents and myself regarding Session?

All of those. Essentially you would have to go out of your way looking specifically for incompatible clients.

And “incompatible clients” is simply the natural state of any technology that’s been around long-enough. The only way Signal fends itself from this is by mandating its own client and version (and banning anything else, technically or from its ToS) which is terrible for a bunch of reasons (you must agree with Signal’s direction and whatever features they might decide to add and remove for your own good, you cannot use Signal on devices/platforms that Signal has no resources/interest to support, etc). If Session is in any way open, and assuming it ever becomes successful, it will face the same challenge (just like Matrix does).

Everything you might use relies on a protocol down the stack. XMPP happens to be the only one to date that is an internet standard (IETF), is extensible by design (past/present and future use-cases can be build into it, what makes it still relevant 25 years later), is federated (but not P2P, a good trade-off for mobile usage), has a diverse/multi-partite ecosystem of client and server implementers (sustainable and resilient), and is deployed successfully at scale (on billion of devices).

unless it’s been revised, imparts no encryption

Today’s XMPP uses the same E2EE as Signal/WhatsApp/Matrix/… XMPP had end-to-end encryption 10 years before Signal was invented

What the other responders said (there are great clients out there, that fit mainstream and niche needs).

Also, it is not a problem of “federated protocols” per se, but of community-led projects. On the downside it may lack consistence and direction, but on the upside you can step in and contribute feedback, tests, documentation, and why not, code :)

So, what would be the appeal compared to XMPP?

This isn’t wishful thinking, this is in defense of a model where our digital needs would be distributed at a level lower than that of the tech majors, which was commonplace before everything on the internet was so consolidated.
I’m not saying that everyone should self-host, I’m saying that federated services could be hosted at family&friends/regional/national levels, simultaneously, and deliver a resilient service at a negligible cost. Hardware, which is very much a problem for Signal & al right now, wouldn’t be in a distributed model, and could be donated and repurposed easily. My example was perhaps a bit too extreme, but I think you get the gist of what I’m saying.

Sorry to hear. I’ve been using omemo (e2ee) without a single message lost since… perhaps 5 years ? I also don’t use movim (I don’t trust its model and level of stability/maturity, especially with regards to doing e2ee in the browser). I would not recommend “XMPP via Movim” either.

Edit: a word

I’ve tried both Matrix and XMPP but stuck with Matrix

And so did I but ended up with XMPP instead of Matrix. Self hosting my messaging was important to me, and the cost of doing so is prohibitive with Matrix, the protocol and its implementations are just that inefficient, and there has been no progress in this area for as long as I’ve been keeping an eye on it. In my eyes, Matrix is broken by design.

Now, Element is indeed a decent client, and above the average of all XMPP clients, but what matters is for XMPP to have at least one great client per platform, which is undoubtedly the case. In practice, all my daily messaging happens over XMPP, the people I interact with are far from the nerdy type, and to them it’s pretty much equivalent to WhatsApp & al.

Back to Matrix, besides the fact that after a decade there hasn’t been any progress towards diversifying implementations (it’s so messy, complex and changing that it’s basically the same people implementing both client and server sides, and there is only one viable implementation to this day, by one entity), which is a big fat red herring, the entity who’s behind 95% of the code of Matrix is now facing severe financing challenges. The future of Matrix is all but certain because of that, and there are reasons for concern.

I don’t “hate” Matrix/Element/the Foundation, I just don’t understand why they painted themselves in the corner they are in today, and rode the pipe dream of their broken protocol for so long. Would they cease to exist, it would look like natural selection to me. They are just not competitive and sorry if it hurts.

I laid it out elsewhere in this thread, but in short, costs grow non-linearly with scale: you can run thousands of users on a RPi, but a million users requires whole datacenters. Decentralization not only helps with not requiring “whole datacenters” in the first place, they also enable maximization of resources: if you have a NAS at home, or a RPi hanging around, a router idling somewhere, or an abandoned smartphone in a drawer, you can probably host enough accounts for all the people that you’ve ever met in your life. And there are hundred of thousands of such underused devices everywhere, which, put together, would be sufficient to host the whole world multiple times around.

The other issue is sustainability: with this centralization comes single point of failure. It’s no big deal witnessing the disappearance of one or few providers of a federated network. Accounts and data can be migrated easily. For most users, it’s invisible. Now compare this to Signal running into financial issues: you are contemplating million of users losing access to their account and their data, and having to re-bootstrap their whole social graph elsewhere. This is another level of “cost”, or price to pay, for centralization.

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Agreed. Not ideal vs. a federation, because Signal would still be in a position of total control over the network, but with less incentive to go against its users.

XMPP

As I wrote elsewhere in this thread, XMPP would be my preference. It just works. In fact that’s what the other messengers (at facebook, Google, …) already use, but chose to put behind a walled-garden.
What matters is that whatever comes next (or, from the past in the case of XMPP) is federated, so no single organization has a single-handed control/monopoly over the network. Matrix and SimpleX are federated alternatives to XMPP, but I don’t see Matrix stabilizing any time soon, and SimpleX just isn’t ready yet. XMPP can offer you today an experience that’s comparable to WhatsApp/Signal/Telegram/…

Signal isn’t a federated protocol, so even if they were incentivized to release all the server bits and pieces, it would not help. You could run your own, but wouldn’t be able to reach-out to your friends running theirs.

Yup, it has a cost, but there’s perhaps a one or two orders of magnitude cost difference between hosting instant messaging + calls with something like XMPP, and hosting mastodon/Lemmy/Kbin (or why I do the former but not the later, and why I’m ok to pay for the service, esp. considering that my instance’s business model isn’t, unlike Reddit, to re-sell influence and data).

Decentralisation would just spread the costs

…the costs and the risks: let’s jump forward a few years into financing issues, at what point does Signal become a liability and start operating against their stated mission, if the alternative is that they cannot survive? We are witnessing enough contemporary examples of enshittification to know that it’s a real possibility, and that all centralized providers, but in particular the ones not charging for service, are at risk.

Some would even argue that this has already started in the case of Signal with their crypto payments and blocking of 3rd party clients which are clearly user-hostile.

Those individuals would have to collect contributions from their respective communities.

Perhaps, or perhaps not. Running costs get exponential with scale. You can host 1000 users on a shoebox computer/raspberry pi, but delivering a service for millions requires datacenter-level infrastructure and tons of engineering know-how.
Most people into self hosting or having a NAS at home can already accommodate their families, friends and more, which means millions of potential users, without the problem of trust from a single organization

I haven’t been able to trust them since the get go, to be honest. Their whole stance against federation is… FUDdy to stay polite: https://gultsch.de/objection.html

Well, if SMS is dead then RCS is what we get instead, and there’s no difference to us (and probably higher costs for Signal & al.)

And there are wayyyy too many things that depend on SMS for it to be dead any time soon, too :)

No, I think they are merely working on user ids no longer mandating to be your phone number (so that it can be pseudonymous, e.g. tja@signal instead of +xx0123456@signal), I don’t believe they hope to drop SMS verification at this point because of the spam issue getting worse otherwise

Without SMS verification, spam would be so much worse that they’ve been kind of obliged to keep it, even though it defeats/undoes most of the privacy features they like to advertise about

I cannot really root for threema here because of its centralized nature, although I do appreciate that it has a saner business model than Signal

If those “normies” aren’t turned away by the creation of an account (and if they can use Amazon, I doubt it’s an issue), they can certainly use XMPP :)

Here to pick a provider:
https://providers.xmpp.net/

Here for the software:
https://xmpp.org/software/?platform=android

https://xmpp.org/software/?platform=ios