My guide to FOSDEM – Europe’s biggest open source developer conference

FOSDEM sign - by Elizabeth Krumbach Joseph, used under CC-BY-2.0FOSDEM stands for the “Free and Open Source Developers European Meeting”. It is a conference aimed at, you guessed it, developers working on Free and Open Source software. The event takes place once a year, over two days in Brussels, Belgium. It has been running since 2000.

Bytemark staff have attended several times, so I’ve put together this guide which I hope encourages you to take part as well.

What is special about FOSDEM?

If you’re familiar with the tech industry, then you know that there a literally 1000’s of developer meetups and conferences taking part across the world each year. So why should you attend this one?

Firstly, FOSDEM is described as “Europe’s largest meeting of Free and Open Source Software Developers”. There are over 5,000 attendees. That makes it one of the best opportunities on the continent for meeting likeminded individuals and sharing ideas.

But what makes this conference really unique, is that it’s completely free to attend and has no pre-registration or ticket requirement.

Who is it for?

Although it’s described as a meetup for developers, people who attend FOSDEM come from very mixed backgrounds. I didn’t feel at all out of place as (primarily) a sysadmin.

With so many talks, there is something for everyone. From 3D printing and Raspberry Pi’s to cryptocurrencies and DNS – there’s bound to be a topic that sparks your interest! That said, you’ll probably find developers of most of the software projects that you use at FOSDEM, particularly if they are based in Europe. Which is also a pretty cool reason to attend.

Travelling from the UK

From the south of England, it’s simple to get to Brussels on the Eurostar. Bookings open 120 days before departure so put a note in your diary to get the best price. Bytemark has also had experience sending 6 members of staff on the train from Manchester, which was also straightforward.

Once there I’d recommend using the trams to get around town – you can get a tram ticket from the small orange machines near tram stops and they have an English language mode. It’s probably worth getting a “10 trips” ticket when you arrive, as this can be used for more than one person on the same trip.

When you’ve purchased your ticket, get onto any tram and then insert the ticket into the orange machine on the tram, which will be close to the middle doors. Insert it once per person travelling in your group – the machine will click and the ticket will be marked on the back to show the number of journeys used/remaining.

Walking around Brussels is also very easy (though may depend on the weather at that time of year!).


As I mentioned, FOSDEM takes place over two days. The exact dates have varied slightly over the years, but it usually takes place at the end of January or start of February. FOSDEM 2019 is scheduled for 2 – 3 February.


FOSDEM is unique as you can literally just walk off the street into the venue and straight into a talk from leading open source developers – without registering in advance. It almost feels like a bunch of smaller conferences all happening at the same time but in the same venue; you’re free to move between them as you wish.

There are five different types of activity: keynotes, main tracks, developer rooms (devrooms), lightning talks and certification exams. You can learn more about all of them on FOSDEM’s website.


The conference is currently held at ULB, a university in Brussels. The venue is large, with one main lecture theatre that’s big enough to hold the thousands of attendees, as well as dozens of smaller seminar rooms where smaller sessions are held. The site is spread across a few different buildings.

fosdem logo

There’s junk food on site (chip stands etc) plus vending machines and a few other options, including a canteen hidden round the back of one of the buildings that I only discovered on the last day of the event!


The bulk of the activities take place in devrooms: independent streams of content managed by their respective communities and planned well in advance of the conference.

Each devroom will have an assigned physical location, plus a schedule listed on the app/website. Some devrooms will only run on either Saturday or Sunday, while other larger ones may run for both days.

It’s definitely worth getting the app and checking the schedule in advance to work out what talks you’d like to see.

Some rooms will be constantly oversubscribed, so if there’s a talk you particularly want to see, you might need to wait well before it in the vain hope that some people leave and make space for you. Other rooms might have a green sign on the door indicating you can enter quietly and find yourself a space.

Attendees don’t empty out of rooms between each talk, so if you’re very interested in something it may be worth attending at least the talk before and just staying in the room.

FOSDEM is a great place to learn from some of the best open source developers in Europe and it’s completely free — you just need to get there. I hope this article has helped demystify the event and help set your expectations. If so, I look forward to seeing you in Brussels!