XMPP Summit - 2026-01-30

emus: the setup was perfect today, I would not complain if there were mandarines instead of bananas (since I prefer mandarines), but there was plenty enough to eat in any case 😋

https://images.assettype.com/barandbench/2026-01-27/5ol8a72t/Meta__WhatsApp_complaint_.pdf

Maybe we should use that when lobbying for decentralized systems...

Heise article (in german): https://www.heise.de/news/Sammelklage-WhatsApp-Verschluesselung-angeblich-unwirksam-11156854.html

(Sorry Thilo not to distrub your discussion) Would someone do me a favor an take the (small) pack of stickers today for tomorrows Fosdem? I also have to carry the handouts and wont be that early at the Fosdem.

We have plenty of stickers

debacle, celeste, are you walking to the venue? If you let me know when you plan to leave the hotel, I could try to join you on the way

> We have plenty of stickers Okay, still can someone help as I dont know how much I will have to carry ↺

Karel we go around 8:40

Im running a bit late, but will be there in 20 mins

Karel we are going now. See you there!

Haven't quite escaped the NH yet

I'm planning to leave NH at 9:15

On my way

Forgot something in my room. I'll be down in two minutes

We're back online with audio. Video will arrive shortly.

https://calls.disroot.org/XMPPSummit28 for anyone who forgot :).

sealed sender and onion routing are one topic: no?

We’re starting with a lightning talk from nicoco right now, FYI for the people in remote

singpolyma, not necessarily

you can't do (useful) sealed sender without onion routing and I'm not sure what you'd accomplish with onion routing other than sealed sender/recipient. so it seems like they at least need to get discussed together

singpolyma, I think daniel introduced it by talking about SASL anonymous

but we’ll see

nicoco: I filed a ticket for myself for you at least now: https://soprani.ca/todo/533

I'm going to probably draft XEP soon for link preview. it's time now with three implementations

https://nicoco.fr/summit28/ for the on-screen slides

º

This person attempted to retract a previous message, but it's unsupported by your client.

slidge.im seems to be down.

host gateway but not host server is totally doable with https://xmpp.org/extensions/xep-0225.html ;) I mean admin has to allow you a "component account" or whatever but that's all

I don't see how OMEMO to gateway is any kind of improvement. However, for the UX concern this is "easy" to solve by having the app detect it is doing OMEMO to a gateway jid and display differently to not promise e2ee (if they app indeed shows anything)

I'm not sure that designing based on "some client might not show what we want" is ever going to be sensible. There will always be some app that doesn't do what you prefer. All you can do is not suggest such a client from eg your gateway website

Same point as yesterday: If you want to raise any point to the round, please tag it with SUMMIT

nicoco: Will you be able to fix soon or will it take time?

because I would like to drop a post

SUMMIT: if you don't deliver at least somehow via your server don't we lose all possibility of multi device message history?

> Same point as yesterday: If you want to raise any point to the round, please tag it with SUMMIT So we'll need to add #hashtags support in XMPP, new topic ! ↺

#hashtags mentions ?

<tag xmlns='urn:xmpp:hashtag#1'>wibble</tag>

Could be

Would be also awesome to have them in vcards or descriptions, would really ease the search and discoverability feature

singpolyma, ah, I just relayed you without knowing :)

(Atom have already <category/> for that for Pubsub Social items, so that's fine)

MattJ: great minds

http://mathieui.net/part/slides-summit28.pdf here’s the slides I had prepared for onion routing, FYI (does not appear to work on the room wifi, but my server is up)

There is a XEP about labeling messages

Just in case anyone is not aware, for onion routing it's worth looking at https://en.wikipedia.org/wiki/Mix_network / mixmaster remailer etc and how that all used to work

> nicoco: Will you be able to fix soon or will it take time? ahem let me try to do that right now, I don't understand anything about the current topic being discussed anyway :) ↺

> There is a XEP about labeling messages Which number ? ↺

I do like the idea of doing remailing / onion routing sealed sender stuff, but I don't know how we handle multi device here and I think that's the main thing we'd need to think about.

> I do like the idea of doing remailing / onion routing sealed sender stuff, but I don't know how we handle multi device here and I think that's the main thing we'd need to think about. CC: Daniel ↺

mathieui: Slides loaded on my laptop, if they're needed on the big screen

singpolyma, could be done with encrypting to your other devices, in the same message (possibly in another element), and let your server archive that and drop it when forwarding

Fishbowler, thanks, we’ll use it when we get to that topic

mathieui: yeah, some kind of "write to my archive" operation that doesn't actually send anything

> edhelas wrote: > Which number ? It is for security : https://xmpp.org/extensions/xep-0258.html But could be use more largely ↺

security labels aren't really "label" in the sense of tags

258 is very much only about security labels, and that's nothing to do with tags.

Ok, sorry

SUMMIT: doesn't MLS allow out-of-order within a small window? Last time I looked at libraries there was a setting for how tolerant to be of this kind of thing

mremond: I see how you would think it was similar, because it includes display markers, but there are routing and security implications for any system along the way that is label-aware, so you can't just do anything random, it usually has to agree with configured label catalogs and clearances.

Yes, thanks. Indeed, not a good idea to extend the scope, especially for the server that would need to check for extra rules to apply for those messages

Wire is advertising MLS implementation

https://wire.com/en/messaging-layer-security

at least we know that keeping the 2-days format was a good call, it would have been pretty tight to timebox topics otherwise

IMO (and I know this is basically what Daniel said IRL) the draw of MLS is that there are and likely will continue to be libraries implementing it. If we ended up "still needing OMEMO" for anything at all it becomes much less interesting very fast

And forward secrecy protocol is going to be designed to prevent archives :) that's the core purpose. if you have an archive, you've defeated forward secrecy

Does anybody know how to spell the name of this 'air' MIMI messenger? Sorry I can't find any information about it online :(

Just Air. I think air.ms is theirs, but that's a placeholder.

I found this at least: https://play.google.com/store/apps/details?id=ms.air&hl=en-US

You can learn more about air at fosdem apparently https://mastodon.social/@phoenix_r_d/115983471536996670 ✏

thanks!

https://phnx.im/ is Phoenix R&D GmbH's site.

I left the conference, please tell us when you come back 🙂 ✏

nicoco: https://github.com/xsf/xeps/pull/1499

Rémi et al.: we're back into the room

And goffi is starting his lightning talk

SUMMIT: Could the server where the end-user’s account is define what the default scoring algorithm should be? So, to continue on your example, all firefighters would have a certain default without having to ask each one when they start their client? ✏

SUMMIT: Could the server where the end-user’s account is define what the default scoring algorithm should be? So, to continue on your example, all firefighters would have a certain default without having to ask each one when they install their client? ✏

SUMMIT: Could the server where the end-user’s account is define what the default scoring algorithm should be? So, to continue on your example, all firefighters would have a certain default without having to ask each one when they install their client? It wouldn’t be the responsibility of the client developer to decide for litteraly anyone on Earth. ✏

could, but for most users that just moves it to another entity which doesn't know who they are or what they need

True, but at least that would narrow the user profiles 💁🏻‍♂️ For non-public servers (e.g. companies, hospitals…) that would be a good middle ground IMO

> SUMMIT: Could the server where the end-user’s account is define what the default scoring algorithm should be? So, to continue on your example, all firefighters would have a certain default without having to ask each one when they install their client? > > It wouldn’t be the responsibility of the client developer to decide for litteraly anyone on Earth. I dont get the first sentence. The semantic confuse me ↺

> True, but at least that would narrow the user profiles > That?

Could the server where the end-user’s account is define what the default scoring algorithm should be?

something is wrong in the sentence

is define?

definded?

Could the (server where the end-user’s account is) define what the default scoring algorithm should be?

^ this

that new sentence misses also a noun after 'the' ✏

Could [the server where the end-user’s account is] define what [the default scoring algorithm] should be? Better?

> SUMMIT: Could the server where the end-user’s account is define what the default scoring algorithm should be? So, to continue on your example, all firefighters would have a certain default without having to ask each one when they install their client? > > It wouldn’t be the responsibility of the client developer to decide for litteraly anyone on Earth. CC: goffi ↺

Sorry, my bad

it's always a bit weird to talk about "the people" as if it were a unified monolithic entity 😬

>> SUMMIT: Could the server where the end-user’s account is define what the default scoring algorithm should be? So, to continue on your example, all firefighters would have a certain default without having to ask each one when they install their client? >> >> It wouldn’t be the responsibility of the client developer to decide for litteraly anyone on Earth. > CC: goffi I'm not sure to get well the question. The score is per-service, not per-user.

SUMMIT: I like the idea of safety number, but then if we talk about auto-removing no longer used omemo keys won't the safety number change when this happens?

Guus's slide: https://docs.google.com/presentation/d/1E1EfbZpJjWrEpsQS3nPZLHZIRysIYTHiXWeT_wZoBEA/edit?usp=sharing

more docs

Off-topic regarding Berlin sprint 2026: Wikimedia wrote again. We get the room again! It will be either 12.-14. or 19.-21. of June. They'll inform me later about the final date. Ignore me.

specs are cool but need more docs

FWIW in ddg and google, the first thing that pops up for me with "interoperable chat standard" is a blog post from engineering.fb.com "Making messaging interoperability with third parties safe for users in Europe"

Summit: In general I think it's imporant to never assume, that the person you are talking to has the same knowledge as you. And in this specific case, that they are basically defining xmpp, couldn't be to our/your advantage? I mean procurement laws prohibit from writing "we want microsoft", so they write, "we want a company to sell us" and then make the paremeters so, that only microsoft products fit the description.

(By the way sorry, if that point made before. It's really hard to type and follow the discussion at the same time) ✏

Summit: Why I made the general point. I was at a standards working group meeting. Something about fire protection in buildings. They meet every other year. One of the members of the group (I guess he's an engineer?) , did some "homework", that he was supposed to present to group. What he did, was put some data into a software and he present the result. A number… He got asked. "What does that mean?" He, an engineer, a regular member of that group, literally could not explain, what the significance was.

Psi also had Windows and Mac builds, but web clients are also important for desktop.

yeah. I already point most of my windows customers at my web client even though it's in alpha because it meets their needs best often

when I get to beta I'll do a tauri thing

> specs are cool but need more docs Code is more fun than docs. And I'd rather write docs than a marketing blog post. But maybe this is a marketing problem.

indeed

https://2024.matrix.org/documents/talk_slides/LAB4%202024-09-20%2011_00%20Julie%20Ripa%20-%20Tchap_%20the%20French%20administration%20federation_%20past_%20present%20and%20future.pdf

https://upload.movim.eu/files/9d94237298995552fa13436420195fbca436dce7/zKiZXbbNmuvt/chat_image.png

> Psi also had Windows and Mac builds, but web clients are also important for desktop. gajim has a .dmg thing for mac os now, and is on the windows store too ↺

(if we talk too much about jabber/xmpp we’ll summon Ge0rG who will suggest zimpy)

"XMPP, pronounce it "ximpy" as in the TV show "Ran and Ximpy" 😉

Rebranding things with new brands starting with X is always risky :p

Zimpy, avoids the X.

celeste, I just stay with "Jabber" no matter what, esp. since I see a lot of "XMMP" and "XMTP" on Mastodon: https://framapiaf.org/@debacle/115978808564597330 I just don't care about the black Cisco van with darkened windows in front of my house.

the way trademark works they can't "come after you" for most of the ways we as a community use the word anyway

Currently, yes. But if we want to expand the ways we currently use it...

debacle, wait until we leave the summit place before using the word, cisco belgium is not *that* far

but some people remain scared and always will. which is the problem

it's not a legal problem. it's a perception problem

> (if we talk too much about jabber/xmpp we’ll summon Ge0rG who will suggest zimpy) https://www.urbandictionary.com/define.php?term=zimpy ↺

As a commercial entity, you won't want to use a trademark and/or product name of a competitor.

not as the name of your company or product, no

in reference to the network you interoperate with, though, which is how we use it

Marketing a Jabber server or client that doesn't work with Cisco Jabber is only adding to the confusion.

We need Jabber 2.0

Jibber.

J2bber, This time it's serious

could ask them to affirm the existing license so we're not scared to use this contract we already have? heh

the main reason they want to bind us to a licensing agreement is that due to non-enforcement in this area the trademark is effectively unrestricted without it

having an agreement sets boundaries and ground rules, which is a win for them

I assume that's part of why they did it in the first place

Video is gone. Who said process one would never use the word Jabber... isn't their flagship XMPP thing named ejabberd?

Fair point :).

J in JID and Gajim is also for Jabber, btw.

Gajim as Another Jabber Instant Messenger ?

I would have to rename slixmpp to slibber, which does not sound very good

> "XMPP, pronounce it "ximpy" as in the TV show "Ran and Ximpy" 😉 Trauma ↺

Isnt it Stimpy?

And Ren, but that's not important for the joke.

relying on the continuing goodwill of a megacorp that doesn't know we exist seems like a bad move

I do already say "snikket compatible" in some places alongside saying "jabber"

> relying on the continuing goodwill of a megacorp that doesn't know we exist seems like a bad move it's not good will. it's established law + a contract. but the discussion was about having cisco re-affirm / re-negotiate the contract ↺

moparisthebest, that’s why getting at least one recent statement (or even a promise) would be good to know where they stand

1 current employee can say whatever now, doesn't matter, relying on the continuing goodwill of a megacorp that won't remember we exist tommorow seems like a bad move

contract law isn't goodwill

have you looked at the contract?

singpolyma, there is contract law and then there is a megacorp sending an army of lawyers to shut you up

i was reading it just now

mathieui: nothing in this world will stop them from sending lawyers if they suddenly want to. no matter what word you use :)

so on that basis *everything* is goodwill, heh

How about we normalize saying "I'll send you a message via SMTP" instead of "I'll send you an email" so that it's totally fine to keep on saying XMPP? why should *we* change, right? ;)

if the current contract is valid, if, it requires the JSF to police use of the trademark, and if they don't, contract void

singpolyma, yes, but then there is prodding the IP of a megacorp and there is just being outside of their field of view

Where's xsf's legal team doing this?

indeed. as I said, setting up ground rules like that is the reason cisco agreed to it in the first place

look I agree legally, per fair use, it's probably fine... but most of us don't have the millions required or time to fight cisco in court to prove it, so pick another name

> Where's xsf's legal team doing this? I think we're effectively dealing with all current misuse (in that there is none) ↺

if you pick another name you still need the millions to fight. common law trademark is a thing for example ;) they can always come

what actually matters as mathieui says is if they notice you or care

since we have plenty of xml elements in the protocol, maybe we could rename the protocol to Element

which we have decades to see that so far they don't

>> Where's xsf's legal team doing this? > > I think we're effectively dealing with all current misuse (in that there is none) I even agree, but our opinions don't matter, only the opinion of 1 of cisco's army of lawyers who can singlehandedly make our lives hell does ↺

For reference, more information on the Jabber trademark agreement: https://xmpp.org/about/xsf/jabber-trademark/

> For reference, more information on the Jabber trademark agreement: https://xmpp.org/about/xsf/jabber-trademark/ and XSF hasn't enforced that in years, which alone is all cisco needs to call the agreement void ↺

let's do a screenshot of every client and every page load shows you a different one ;)

moparisthebest: I don't think that's true? XSF is effectively enforcing it

saying "no one has broken the agreement" is not "no enforcement happened"

these are all silly legal arguments though, for me the simplest one is when I search jabber only cisco stuff fills the first page

There have definitely been cases around the trademark that Board has handled over the years. We don't shout about that

sure. there's a difference between being allowed to use the word in certain ways and wanting to. which is where we started here

Can me make a small break after this talk?

I don't think anyone is gonna change their opinion on this, i don't want to confuse new users searching, or risk a legal action from cisco, so I'll never say jabber

now lets agree to call them XIDs ;) 🧌

moparisthebest, I think that you completely misunderstand the trademark agreement and our role in it. I suggest you read the material I linked.

I did, what am I misunderstanding

oh that page doesn't have the pdf agreement with cisco which is what i was talking about

emus: In regards to the "professional" recommending joining propietary "social" media. Not necessarily. I mean, the FSFE, "Open Source Initiative", OSBA. They all work more or less "in the background" and directly with businesses, lawmakers and administrations.

I tend to agree with @celeste that I am now getting used to Zimpy and it could be the name not of a product but of a mascotte (another light bulb form ?) that implementers could reuse ? It may be worth trying to see if people adopt it.

Yay mascots :3

And we can fund Ralph by selling Zimpy teddy bears

like i know it:s kind of silly...but already zimpy has a movement......zooom......it's also oddly retro and dorky but in an approachable way. dorkyness, diversity etc.....i am beginning to sound like a marketing person....

celeste: congrats, you're now in charge of marketing

Can't wait for the Zimpy cosplays at the XMPP Convention ✏

> emus: In regards to the "professional" recommending joining propietary "social" media. Not necessarily. > I mean, the FSFE, "Open Source Initiative", OSBA. They all work more or less "in the background" and directly with businesses, lawmakers and administrations. I was responding to those concrete requests (Facebook, Insta...) ↺

moparisthebest, the page I linked has side navigation that will bring you to the right documents. But specifically, we are *not* required to enforce the trademark as if we were the trademark owner.

If you’ve personally proposed investing time or energy on something, please write it yourselves in the Pad (https://pad.nixnet.services/I-8sGqciQjiALG30YE60iA?edit), I didn’t want to make mistakes while not even sure about who was speaking

https://fosdem.org/2026/schedule/event/7XJL9E-engineering_xmpp_federation_building_messaging_voice_social_features_across_inde/

https://fosdem.org/2026/schedule/event/EVSXLA-movim-building-decentralized-social-network-xmpp/

> 📢 Movim: Building a Decentralized Social Network on XMPP > 📍 Room: AW1.126 > 📅 Day: Sunday 1st of February > 🕛 Start: 13:45 > > In this conference we'll discuss the technical challenges of building a rich web frontend on top of XMPP, showcase the exciting features recently added to the project, and introduce the upcoming planned ones.

I assume you will add this to our own wiki page in a moment, so we have all the information in one place so we won't have to look for it everywhere.

Yup, little hands are currently doing it ✨

Also, “[y]ou are not allowed to bring fridges, coffee machines or any electrical appliances like this!”

I’ve added the talks to the wiki page

:)

https://compost.party

https://archive.is/w78l4

it's more online during the summer.....

"Dear Friend, I hope that my <stanza/> has finally arrived, the wind was blowing the past few days and my server..."

edhelas, did you think of https://lists.openstreetmap.org/pipermail/talk-nl/2011-September/013148.html ?

I don’t speak much dutch though

https://www.ffi.no/en/publications-archive/cross-domain-communication-using-an-xmpp-chat-guard

https://www.wizbii.com/company/thales-communications-security-s-a-s/job/stage-bac-5-dveloppement-de-messagerie-instantane-h-f-3

Job offers at Thales looking for people on SIP/XMPP :D

fact: Researchers in Antarctica host Prosody for instant messaging

https://prosody.im/testimonials

+1 on corridor discussions, that’s partly why I said I prefer in-person

Have to go sorry my coworking is closing, hopefully you’ll still be there in 15 minutes

So it's worse than I remembered? https://xmpp.org/docs/Trademark_License_Agreement.pdf these are agreements not between cisco and xsf but between jinc and jsf lol, seems fair to assume lawyers at cisco don't even know these exist It also says jabber can't be used with any commercial project without written permission from JINC. That means jmp/cheogram/ejabberd etc etc aren't allowed to use it right? (per this agreement anyway)

Will onion routing slides be posted somewhere online?

https://xmpp.org/docs/Trademark_Enforcement_Agreement.pdf is even worse because it clearly expired may 4 2004 right?

Ejabberd precedes any of that I think

I'm on my way to Brussels, would be cool to get a ping with the location once the dinner plans have been decided upon

https://mathieui.net/part/slides-summit28.pdf

Thanks

> zeank wrote: > Ejabberd precedes any of that I think Yes, ejabberd started the 16th November of 2002 ↺

xtls: https://www.ietf.org/archive/id/draft-meyer-xmpp-e2e-encryption-02.html

Thank you for this Summit and for making remote participation possible! See you next time, hopefully in person

Are there any dinner plans?

Daniel, i and Matthew are at the grand placa

It was nice getting to see you all ! Enjoy Fosdem !

Thanks to everyone who made me so welcome on my first Summit.

Thanks to emus for organising, for everyone who did note taking, and to everyone else involved in making a smashing 2 day event.

Thank you! That was not only on me but also Daniel, Guus & Ralph! Special thanks to Edwin for helping out and you Dan! Thanks for everyone coming and making the even fruitful!

> Daniel, i and Matthew are at the grand placa Are you still there? ↺

any other folks I can join?

Neox, mathieui, edhelas and I plan to eat something, did you do that yet? Are you at the beer event?

(If edhelas arrives one day)

> Neox, mathieui, edhelas and I plan to eat something, did you do that yet? Are you at the beer event? Im leaving my flat now and have done nothing in that regard. I would join ↺

Cool! We meet you in 15, where are you exactly.

I'm there

Where? ✌️

edhelas, nicoco:

We are at the centre of grand place

emus: where are you exactly?

Midi ↺

Oh I thought you were in grand place?!?

Call me xmpp:nicoco@nicoco.fr

Just a quick call via this mysterious performant protocol. Worked ✔️

dwd, you mentioned that you will have some transportation from the NH to the ULB in the morning? Is there still a free spot by any chance? If not, I will come on my own, it's no problem