FOSDEM 2025

I recently attended the large Free and Open Source Software conference FOSDEM 2025 in Brussels, Belgium. I went there by train, of course, via Copenhagen, Hamburg, and Cologne. The same route back.

I lived in the rather expensive, allegedly fancy hotel Le Châtelain in Brussels. It was really not that fancy, but they had a 24/7 reception and perhaps five(?) people there at all times. They also locked the door really early. I think they were afraid of something or someone.

I thought the neighbourhood was fine. Especially Rue de Bailli around the corner was nice. Many restaurants and bars, even though I didn't have the time to visit more than one restaurant on the street.

I spent Friday mostly at the hotel, working in my room, mostly on other things but also preparing my own presentation for the next day. I chose to travel a day early because, well, trains. The trains actually worked out OK, even if a lot of people I met complained about Deutsche Bahn.

Naturally, I was nervous about the food, as I always am when travelling, being vegan and allergic to soy and peanuts. I had researched quite a lot, of course, and I had a stash of Huel bottles and protein bars with me, just in case.

I had lunch that first day at a nice vegan place called Lucifer lives, close to the Palais de justice. It had a punk vibe and a horror theme with horror movie posters everywhere. I liked it a lot. It also had great coffee, much better than the coffee during the hotel breakfast. Btw, 37 euro for breakfast at the hotel! So not worth it.

The statue just next to the Palais de justice gets a special mention: steampunk octopus robot! Yes, please!

My friend A, who lives i Brussels, arranged a dinner for me and a few others at the wonderful East & West restaurant. Meze with something like 18 bowls of different things. Then the dessert came in! I certainly didn't leave hungry.

A then brought me to a party in a pretty nice industrial-looking flat, but I had to leave early(ish) to keep working on my presentation. It was a little adventure to get back to the hotel on Friday night.

The FOSDEM conference was held at the Solbosch campus of the Université libre de Bruxelles, which was about 30 minutes walk from my hotel. I walked there on Saturday.

I was underwhelmed. No fancy signs? No facade lighting? Not even blinkenlights? Just very… worn down buildings and classrooms?

Yes, I suppose I've been spoiled by the Chaos events and especially the Chaos Communication Congress.

OK, I realize they probably didn't have thousands of hackers and artists coming a week early to build, I don't know, things like a castle of neon lights, a huge pneumatic tube systems covering several floors, no less than three different phone networks, Internet-controlled flamethrowers, and setting up things for trapeze artists 10 meters above one of the dance floors (Dance floor? Ha! No such thing.) … and the list goes on.

There were also much less cat ears and alternative clothing, but I was sort of expecting that. I wish I at least had put on some nailpolish. Rabbit ears might have been too much even though #3 would have been delighted.

Most of the actual talks could be summarized with the following sign:

I almost couldn't get in to the Security Devroom when it was time for my own talk! Haha.

I'm afraid my own talk was yet another pretty generic, although updated, presentation about the Tillitis TKey, what it is and what you can use it for. I've prepared more interesting talks but this was the one that was accepted, and I guess people still need to hear about what the TKey is. It's such a simple idea (thanks, Microsoft Research!) but the simple idea and all its implications can be hard to get across.

I was terribly nervous, as usual, and it didn't help that I almost didn't get into the room. I had, perhaps, 20 seconds to plug in my laptop, mic up and be ready to start. Naturally I didn't have any way of testing that my setup would work at all. And… Of course, the Emacs window showing the presentation hid a lot of the bottom of my "slides". Different aspect ratio from my screen. Dammit!

I talked around it and I think it was basically fine. The fuckup naturally made me even more nervous.

I mentioned Morten "Foxboron" Linderud in my talk and his work at one of the Tillitis hackatons bringing up Zig on the TKey. Incidentally, one of my newest colleagues, Mikael Ågren, did the same thing independently around the same time!

After my talk it was Morten's turn! He wasn't even in the room when I held my talk, unfortunately, but I had some time to talk to him before he started. His talk was about "Hardware backed SSH keys: ssh-tpm-agent" and, yes, he mentioned and showed the TKey and the tkey-ssh-agent during his demo! Thanks, Morten!

My almost-colleague Niels Möller from Tillitis' sister company Glasklar Teknik did an introduction to their neat transparency log project Sigsum.

I managed to catch some talks in the devroom for Digital Wallets and Verifiable Credentials, too.

First I saw a lightning talk "Digital identities in disarray" by Amelia Andersdotter and Gregor Bransky about the eIDAS 2.0 proposal and all the confusion around that, but not a lot about the amendment to the original eIDAS (which is now law) and the current efforts to build the European Union Digital Identity.

But the next talk was all about just that! "Challenges for Wallets and Digital Trust Services following EUDI Wallet Architecture Reference Framework & Reference implementation". It was unfortunately cut way before they even had got into the meat of the thing.

Anyway, the gist is that by November 2026 all EU member states will have to start offering at least one Digital Identity Wallet application to all citizens. Scytáles and IIUC partner Netcompany-Intrasoft are working on the technical specs (the Architecture Reference Framework", ARF) and the reference implementation of all parts. It's all awailable… on Github! The ARF source is even in Markdown!

All the repos:

https://github.com/eu-digital-identity-wallet

I had a look through the Wallet apps libraries before just to see what they demand of the actual ID carrier and if, yes, you could use the TKey to carry a private key. And yes, it seems like you could.

While I was waiting in the queue to my own talk I was quite surprised when Isaac Freund, author of the great Wayland compositor River, came up to me and asked if I was MC. Haha. We talked for a while. I really liked that.

I tried to get into Hans "pengo" Hübner's talk about Bildschirmtext, of course, but that room was even fuller than should have been possible. And the hallway outside had the queue from hell.

In total I managed to get in to perhaps three or four talks besides the Security Devroom that I stayed in for a while.

There was some other events in Brussels at about the same time as FOSDEM. First there was the Europen Open Source Awards, which among other things awarded Daniel "bagder" Stenberg a nice price.

There was a lot of other fringe events. Of them I was sort of tempted by OFFDEM, of course. Consider the OFFDEM Manifesto. But this was a sort of work thing, so I stayed at FOSDEM proper.

Considering that FOSDEM is held at the peak time of the seasonal flu season in Europe, some people have apparently more-or-less jokingly called it "flucon" or "fluconf". So… of course, someone started a real FluConf! Naturally, the conference is completely online. Perhaps I'll try to attend next year?

On the way back (Brussels-Cologne-Hamburg-Copenhagen-Malmö) I was hoping to have the time to get to Tünnes und Shäl in Cologne and get a vegan currywurst (yes, really!) and a kölsch, but alas, the train was a little late so I didn't have the time. I did, however, buy some kölsch and took yet another photo of the Kölner dom.

All in all, travelling back to almost exactly 14 hours from leaving the hotel until I entered my front door. Not too bad, with so many train changes.

My experience of Brussels was kind of dark… I saw a lot of unhoused people. My friend A said that the crime rate was bad and things like domestic violence, even murder, was through the roof. Just the week after I came home someone was shooting with fully automatic weapons in central Brussels!

I didn't expect that at all. It was also very expensive. I did expect that.

On the other hand, I found traces of underground culture, in a way I didn't do at all in Paris. That was the good part.

I probably won't be coming back, neither to FOSDEM, nor to Brussels, if I can help it.