FOSDEM 2026

Let’s meet up and talk about green IT at FOSDEM in Brussels. It’s one of the largest open source conference in the world and a great place to learn & meet others.

Join #fosdem where we can share travel plans, event info, and interesting sessions. Let us know if you’re presenting or interested in presenting, and we’ll support you however we can!

For more information, post in CAT’s #fosdem Slack channel and tag @Eugenus Optimus or write an email to eugenus@climateAction.tech

Event info

Date: 31 January - 01 February 2026

Location: Université Libre Bruxelles, Brussels, Belgium (OpenStreetMap)

Website: https://fosdem.org/2026/

Cost: Free!

Key deadlines:

 • Oct 30: Devrooms start accepting applications around these dates.
 • Nov 9: Deadline to submit a stand proposal
 • Nov 16: Deadline to submit main-track proposal
 • Dec 1: Deadline to submit non-main-track proposal
 • Dec 15: developer rooms publish complete schedules

What is FOSDEM?

If you believe the organisers, FOSDEM is the largest open source conference in the world (and definitely the largest in Europe, with tens of thousands of attendees descending upon University Libres Bruxelles, for 2 days.

It is a common annual meeting place for members of climateAction.tech who either live in, or are visiting Europe in February, and common fixture on the tech industry conference circuit.

It’s free to attend, and takes place in Brussels, one of the more centrally connected cities in the region. You can learn more about the conference on their website.

Why is it relevant to CATS?

If you find the things discussed in the CAT slack, or the CAT newsletter of interest, FOSDEM is a good place to meet other members of CAT in person, and learn about the projects frequently mentioned in the community. If you care about the CAT mission, the conference is a good place to for advocating for a greener, more compassionate technology sector and good place to find allies to work with, or meet for the first time.

It’s one place you can see other members of CAT present on a range of topics related to the intersection of sustainability and technology, as well as present yourself. Over the years, a significant number of talks have been given by members (both in person, and remotely), across the myriad tracks offered by the conference.

The many tracks for the conference are a particular strength of the event.

While there are a few ‘main rooms’  for the conference keynotes, with capacity in the low hundreds of attendees, there are usually more than 30 rooms, covering a range of topics related to open source, technology and online community management. This means there are hundreds of sessions available to drop into. For an idea of all the tracks, see the archived schedule from 2025.

Even if you are not too interested in the talks (or for space reasons, you can’t make it into some of them, more on that later) it’s also one of the best places to meet people working on the open source projects you might be using, or find people to work with on future projects too.