FOSDEM. Free Open Source Developers European Meeting. Every first weekend of February. In Brussels. At Université libre de Bruxelles.
I used to say that FOSDEM is a week-long conference compressed into two days. I don’t think it is valid any longer. Should say two weeks now as in the 2025 it was something about 1100 talks. Still during two days.
I also used to say that I can not afford not being at FOSDEM. It is probably the easiest way to meet developers from all the projects I have worked with or was interested in.
But how to survive FOSDEM? Food. Logistics. Clothes. Logistics. Mobile app.
Logistics
Yes, logistics is one of the key factors when it comes to this conference.
Lectures take place in several buildings (AW, H, J, K, U). At the same time. Getting from one to another takes time. You can meet people on a way and decide to discuss something rather than go for a talk.
There is an online navigation tool to show you which way to go from one place to another. This is very handy, especially if you have some mobility issues.
Sometimes it is worth being in the same room for a session beforehand just to get a seat. Limits are taken seriously and when the info on door says “room full” then do not even try to sneak in. You may find a spot and watch live streaming — just remember to have good headphones to not interrupt people around you.
If you need a place to sit for a bit with your laptop, you can go to the cafeteria in the F building (crowded, noisy).
Hotel
Get a place to sleep in the city centre. “Crawling distance from Delirium Café” is perfect as this is where a lot of people spend Friday and Saturday evenings/nights. Also there are several places to get various food, some grocery stores (just check opening hours), pharmacies, GSM shops etc.
Public transport
Use whatever you normally use (Google Maps or similar) to check for public transport. If possible, avoid bus 71 if you go at a popular time and not from the first stop. It gets full right from the start and stays that way until the FOSDEM stop.
FOSDEM transportation page lists several options on how to get to/from ULB.
One of the options is getting to Etterbeek railway station (about a 1.5 km walk) and then travelling wherever you need. This is my favourite way to go from FOSDEM to the BRU airport on Sunday evening.
IMPORTANT NOTE: Up to the 2023 edition there were free buses from ULB to Brussels South (Midi) railway station on Sunday afternoon (15:30 - 19:30). There gave an easy way to get to BRU airport, but they are not provided any more.
Tickets
When it comes to tickets…
First of all, check STIB ticket information for options as they change from time to time.
Nowadays (2023+), it looks like using a bank card is the easiest way. Just enter the bus/metro/tram and tap to pay.
Note that there are some single-use tickets still in use if you prefer not to use a bank card.
Mobile application
As long as your phone is able to run applications, check the Mobile schedule apps page on the conference website and choose one. I use ‘FOSDEM Companion’ on my Android phone.
Install the application at least a week before the event. Synchronize the schedule and start checking which sessions to attend. Ignore the fact that some will overlap. It is always better to have more listed than less — sometimes you sacrifice one due to being in the wrong building or a room will be full so you can take a quick look at the list and go somewhere else.
Internet access
Once you reach FOSDEM there is no problem — conference area provides you fast wireless network access.
If you are from one of the EU countries, then your GSM operator probably provides you with some data limit for “Roaming Like At Home” functionality.
If you are from outside of the EU, then I suggest reading the prepaid with data wiki page. GSM operators stores are in several places in city centre. Or you may even manage to find some at airport but easier to just grab one once you reach centre.
Food
Eat a proper breakfast. Not “just a fruit and coffee” but a proper one. You may not have time to stand in a queue for some FOSDEM food. It is not worth your time.
A better option is to just have something with you. Get fruits, nuts, energy bars, chocolate. Some kind of quick calories.
Or spend half an hour (or more) waiting for fast food. This is still a good opportunity to chat with people.
Social events/gatherings during evenings
There are several social events/gatherings organized by different groups and organizations during Friday/Saturday evenings.
In the past, there was a beer event on Friday evening. Since 2008, it took place in Delirium Café pub (later on whole street leading to it). Many people still go there on Friday. It can be hard to get there due to the number of people. It was an easy way to meet far too many familiar faces. And get a beer (once you managed to reach the bar). Nowadays, many people avoid it due to the crowd.
Beer
Remember that Belgian beer can be stronger than your normal one. Do not drink too much or you will suffer and be too wasted during conference.
Clothes
FOSDEM is in February. Which means winter. So it may mean snow, but it is Brussels, so usually it is either nice or rainy. And you will go into a building and out of building several times per day. Be prepared for it.
Wear proper shoes to walk on concrete and steps, but also on snow, mud and grass. Winter cap, scarf, maybe even gloves. They do not have to be thick ones like for an Arctic winter. Assume a few degrees above 0°C.
Bring a small backpack and a bottle of water. Do not throw it away once it gets empty. You are at a university. You can refill your bottle at several places. Tap water is drinkable.
Trash
Do not put your trash in random places. Use trashcans, and inform organizers and volunteers if you see full ones. Put bottles into places for bottles.
If you can, then stay after the ending session and help to clean up. It is free event, so help those who have organised it for you.
Swag
FOSDEM is a free event. But there is swag. You can go to organizers’ desk and donate money to keep the event going. For 25€ you can get the official t-shirt.
Several projects have their own stands — mostly in K building but there are also other ones in AW (mostly related to embedded space).
If you are a stickers fan (or your new laptop still have some space on its case) then go on a tour, discuss with developers, and see what they are presenting. Grab leaflets, stickers, donate some money (usually in exchange to more premium swag) etc.
Or some funny one like this license for VLC I got in 2019:
Fiancé(e) or family
If your companion is not interested in FOSDEM, you may sign them up for free tour(s). My wife came with me to the conference once, went for a tour each day and enjoyed them.
Other events
There are several meetings taking place right before and/or after FOSDEM.
CentOS Project has event before FOSDEM. It is a nice opportunity to meet developers working on this distribution.
After FOSDEM you can attend OpenEmbedded workshop or Buildroot developers meeting.
Several other projects are having own meetings, developer days etc. You can check list at FOSDEM Fringe page.
After FOSDEM
During FOSDEM all sessions are recorded. If you are speaker then you will get an email with a link to the system where you can approve recording for publication.
My page about FOSDEM videos lists all talks given at FOSDEM since 2012. With links to slides and video recordings (if available). It provides an easy way to check all those sessions where you were not present or want to watch them again.