Notes from FOSDEM 2013

Given that FOSDEM has been going for thirteen years, that it’s all about open source development, which I’ve been involved with for about the same length of time, that it’s held in Brussels, where I used to work, that it’s enormous (about 5,000 attendees), and that it costs nothing to attend, it’s perhaps surprising that I’d never been before. In fact, I wasn’t even really aware of it until late last year.

I’ve been missing out up until now.

FOSDEM is huge: there were twenty-four tracks of talks this year, over two days. You can’t see all of it. You can’t even see 4% of it, what with the time taken to walk all over campus. You can know people that are there and not see them all weekend!

I know that I missed many interesting talks, but I still saw plenty that piqued my interest. So here’s a themed dump of links:

Graph databases

I spent about half of Saturday in the graph database room, mainly because I have the feeling that there’s a whole lot of interesting work going on in that field that’s largely ignored and replicated badly on top of more traditional data stores.

  • Signal/Collect is a system for fast and scalable processing of graphs. Seems conceptually related to map/collect, and has similar scaling properties. Looks easy to write for. JVM-based
  • fluxgraph is a ’temporal graph database on top of Datomic. It allows querying of the graph at arbitrary moments in the past, and computation of a difference graph between two points in time. Developed to meet regulatory requirements in the pharmaceutical business.
  • structr is a CMS built on Neo4j. I couldn’t help but think that it was too clever for its own good: just because you can model an entire HTML document as a graph doesn’t mean you should.

Kernel programming

  • Rathaxes is a DSL for describing and building device drivers. The promise is that it can reduce boilerplate and repetition, and make it easy to decouple hardware interfacing from OS-level code, and thus make it easy to write cross-platform drivers. It’s still very immature, and I think we’re a long way from seeing whether this approach will work in the real world, but it’s a useful avenue of enquiry.


DLNA is a set of specifications for interoperability between entertainment devices. It encompasses addressing and transcoding, and lets a (relatively dumb) smart TV play video from a home server, or a phone push a photo to a big screen. What’s more, it actually exists: it’s widely deployed.

I saw a couple of good demos: in one, the presenter took a photo on his phone, picked it up on a computer, and pushed it to a computer attached to a projector. In the other, the presenter had written a small application that would convert the slides of a presentation to JPEG images and tell a computer running a DLNA renderer (XBMC, in this instance) to show the images on screen. Sounds easier than finding the correct MacBook dongle ….

  • Rygel is a server and associated libraries to serve media to DLNA devices.
  • Dleyna is a counterpart to Rygel: a set of libraries to implement players and renderers.
  • Guacamayo is ‘an Open Source software platform for creating multimedia appliances, including multimedia UPnP/DLNA servers, audio players, and full-featured multimedia centres.’


Besides open-source mobile platforms, breaking out of the mutually-incompatible walled gardens of Skype, Viber, FaceTime etc. was a big theme. The observation that you can’t have secure communications without open source received a cheer from the auditorium.

  • Replicant is a project to take the released open-source parts of Android and write the missing libraries for hardware interfacing, so that you can really be sure that your phone is doing what you want, and not secretly recording you, etc. This is surprisingly difficult, as some phones mediate access to GPS and voice through a closed modem; even if not, shared memory may allow a modem to steal voice and position data. Whilst this may sound a little paranoid, it’s interesting even if you don’t yet live under a repressive régime.
  • Firefox OS looks very good. I played with it on a couple of devices. It seems that a multiple-core processor is needed for decent responsiveness, and even then it feels a bit laggy. It took a long time for Android to sort that out, but I worry that Firefox OS doesn’t have that time to spare. I was happy to see that it copies the idea of Android’s Intents to allow easy replacement and augmentation of basic functions.
  • Kamilio is an open-source SIP server that you can use to set up a Skype-like service in under an hour.
  • ReSIProcate is ‘dedicated to maintaining a complete, correct, and commercially usable implementation of SIP and a few related protocols.’
  • Lumicall aims to provide easy-to-use free calling on Android.
  • Jitsi does open-source voice, video, and chat. Kind of like Skype, only actually secure, using documented and inspected protocols.


The talk on OpenPipe was probably my favourite from the entire conference. The presenter and developer, Xulio Coira, started off playing some Galician bagpipes, and followed it up with an entertaining talk broken up by various recordings and live demos of electronic bagpipe music.

  • OpenPipe is DIY MIDI electronic bagpipes.
  • FluidSynth is a software SoundFont 2 synthesiser.

If you’re anywhere near Belgium next February (the first weekend, I believe), then I highly recommend it. It’s easy and fairly cheap to get to Brussels from London, even though, due to the uniquely xenophobic way in which the UK is governed, you do have to go through three separate passport checks to get back in.


  1. Xulio Coira

    Wrote at 2013-04-05 14:01 UTC using Chrome 26.0.1410.43 on Mac OS X:

    Hi Paul!

    Thank you for your kind words regarding OpenPipe. I’m glad to have contributed to FOSDEM 2013 edition. Hope see you next year!