Attending FOSDEM 2025 was an exhilarating experience for the maintainer team. From the moment we arrived, the energy and enthusiasm of the open-source community were palpable. This year’s event was particularly special for us as it marked our first time having a Flatcar booth, shared with our friends from Gentoo. The diversity of devrooms and the opportunity to engage with contributors and users from around the world made it an unforgettable experience.
As we navigated through the bustling halls, we were thrilled to see the interest in our projects and the meaningful conversations that took place. Whether it was discussing ongoing developments with fellow contributors, sharing updates with users, or simply soaking in the vibrant atmosphere, FOSDEM 2025 was a true celebration of open source and the communities that drive it.
In this blog post, we’ll share some of our personal experiences, highlights from the event, and the key takeaways that made FOSDEM 2025 a memorable and impactful event for our team.
James Le Cuirot ( Chewi )
FOSDEM was madness. The moment I set down my old Commodore Amiga on the table, the gravity in the room shifted, and people were bustling around before I’d even had a chance to connect it up. The next thing I knew, I had the Motorola 68K kernel maintainer standing right in front of me. Other visitors included The Register’s open-source reporter. I continued to feed off the energy, barely moving from the spot, but talking constantly about Flatcar, Gentoo, the Amiga and everything in-between. All this while I struggled to keep the Amiga up and running, but people were delighted to simply see it booting Linux. One person stood there excitedly for a good half an hour just to see it reach the login prompt.
I was nervous heading into my first public talk, but one former Gentoo developer kindly accompanied me as I waited for my turn, and I then felt much better. The talk was over in a flash because the person giving the timing prompts got confused, causing me to rush through it, and there were no questions at the end. Despite that, I still had several people thank me for the talk throughout the day, so I guess I did a good job.
It was very different from my previous visits to FOSDEM, as I only attended one talk. I can always catch the rest later though. Getting to meet so many amazing people is what it’s all about, and I look forward to collaborating with them in future.
Mathieu Tortuyaux ( tormath1 )
FOSDEM 2025 was my third FOSDEM participation (fourth if we count the COVID edition in 2022) - this was the first edition where we had a Flatcar booth and to me it was very special because it was shared with Gentoo folks and Gentoo somehow contributed to lead me into Flatcar and later into the Flatcar’s maintainer team.
During the two days of attendance, I met a few Flatcar contributors (e.g IONOS engineer working on Flatcar support on this cloud provider), Flatcar users that I met in previous events, it’s always good to meet with the community and to share some news and updates around the project from one year to the other. It was the occasion to discuss with folks from the Containers OS ecosystem (FCOS, Cluster API OpenStack) to talk about on-going and next development.
As FOSDEM offers a vast amount of diversity in the devrooms: it’s impossible to cover everything and like the FOSS spirit, you can count on the community to help you catching up on things. This is actually one of my favorite FOSDEM activity: asking folks what they learned or what they have seen during the day.
Danielle Tal ( miao0miao )
This was my first FOSDEM. It was quite a ride! This is a true celebration of open source and the communities behind it. The scale is impressive, with so many tracks, buildings and people. I was staffing the Flatcar booth so did not have the time to explore besides attending the Special-Purpose Operating Systems Meetup BOF.
Yet the crowds this event is attracting is fascinating. So far, big conferences I went to all had commercial focus even if they are for Open-Source projects. I had the pleasure to talk to people that are contributors from all age ranges starting with teenagers to people who have been in the industry for quite a while.
Chewi set up a very cool demo, running Gentoo on Amiga. The Amiga had an external ethernet card that connected to a laptop running Flatcar with qemu that loaded the AI module through systemd-sysext a pre-backed Ollama . It was fun to meet people who helped to develop Amiga, had a lab fixing it and people in their teens that only read about Amiga before and was excited to try it and showcasing modern technologies on it.
Adrian Vladu ( ader1990 )
This was my 5th time at Fosdem, always enjoying being at this conference to learn and learn more. This is the place where you can find what is new in the free open source world, and interact directly with the maintainers of the major open projects. Was amazing to attend discussions like the one started by Daan De Meyer on the future of systemd dogfooding - ‘Can we make Lennart Poettering run an image based distribution?!’.
This year was more special, as I also had a presentation that got great feedback and discussion for tens of minutes after it ended: Add RISC-V support to your favorite operating system. Of course, the star of the show was Flatcar :).
People in the open hardware community are really hyped about the emergence of RISC-V and the great future prospects it comes with. Let’s see what the future holds for this open source ISA!
One other great thing was to catch up with Gentoo / Flatcar users and maintainers, see what are they working on, and most important, get some important feedback from the users side. Going to the Gentoo and Flatcar booth, I realized that I want an Amiga of my own.
Thilo Fromm ( t-lo )
FOSDEM has grown to be a family tradition (of sorts) over the years. My wife introduced me to the conference, my daughter has become a regular attendee of the Kids track, and I bet there are FOSDEM t-shirts from as early as 2012 hiding somewhere deep down in the closet.
This one was very special, though. For the first time we had a project booth for Flatcar - and even better, we shared the booth with our upstream, Gentoo! Booth attendance was overwhelming (in a good way): we had a lot of great chats about Flatcar and how it benefits from Gentoo’s enormous flexibility. I was also very excited to learn first-hand about the impact of our upstream contributions - Gentoo maintainers praised our efforts and seemed quite happy with our work. We also chatted with many current and future Flatcar users, and discussed specifics of the distribution - it’s always great to get user input on the project to help shape the direction we’re taking.
The CNCF’s Special Purpose Operating Systems working group (part of TAG Runtime) held its second BoF at FOSDEM . Maintainers of Eve (LinuxFoundation), KairOS (CNCF), Flatcar (CNCF), and SUSE MicroOS exchanged experiences and learnings.
I gave a talk in the Containers devroom - “Immutable All the Way Down - using System Extensions to ship Kubernetes” . Sadly, the 25 minutes slot was a bit tight, so the presentation was rushed. But as has become tradition in the Flatcar project, both slides and infra-as-code of the talk are available on GItHub: https://github.com/flatcar/flatcar-demos/tree/main/FOSDEM2025/kubernetes-plumbing . Included are step-by-step instructions to allow folks to run demos from the presentation - like in-place upgrading the OS and Kubernetes - entirely locally, at their own pace.
Conclusion
FOSDEM 2025 was an unforgettable experience for the Flatcar maintainers. From the excitement of our first-ever Flatcar booth to the engaging discussions, technical deep dives, and inspiring community connections, this event truly reinforced the power of open source collaboration.
We want to extend a huge thank you to everyone who stopped by our booth, attended our talks, and shared their insights with us. A special shoutout to our friends at Gentoo for sharing the booth space and making it a welcoming hub for open-source enthusiasts.
Most importantly, we deeply appreciate the volunteers and organizers who make FOSDEM possible year after year. Your dedication to fostering an inclusive, knowledge-sharing environment is what makes this conference so special.
We left FOSDEM 2025 energized, full of ideas, and eager to keep building. See you next year!
