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An interview with CERN’s Joaquim Rocha

Its been quite some time since we interviewed Joaquim Rocha who was a part of Igalia then, developing the amazing Skeltrack library. He then left Igalia to work for Red Hat and only a few months later took the opportunity to work in CERN, so he has a lot of interesting stuff to share :)

Last time we talked, you were working in the development of the amazing Skeltrack library. What happened since then for Skeltrack?
I think we last talked on June 2012. Since then, Skeltrack has had about 4 new releases. It is more stable now, allows to use a camera in a vertical stance, and is about 4 times faster!
In November, while working for Igalia, it was used as the main component for an installation made for the Museum für Kommunikation in Berlin. It also got two awards, one for innovation — by the KNetworksFwd: initiative at the Oxford University — in November 2012, and another for “best software developments” by Eganet — a Galician associtation of internet/software companies — in February 2013.
Who is the main developer of the project now? Do you have any kind of contribution or involvement with the project now?
I am still the maintainer/main developer of the project. That’s one of the great things about working in Free Sofware: you don’t need to stop contributing to a project just because you no longer work for the company in which it was created.
Iago López, who is using Skeltrack for his University’s final year project, has also had a very important role in, for example, improving the performance of the library.
Some months ago, you decided to leave Igalia and seek for a new opportunity. What would you say to people who are afraid to seek new adventures when all is going pretty well with what they have?
This might be a tricky question :)
Change is good, especially when there’s a desire to have it. You always learn by working or living in a different place. I have lived in four countries now and that has been a great thing in my life.
That said, it doesn’t mean that everybody should do it. I don’t usually take decisions simply based on hunches; there needs to be a good deal of reasoning too (especially if they leave their jobs without looking for a new one first, as I did).
I find having ambition a good thing but if people are happy where they are and have no curiosity of trying new challenges, then I think that’s perfectly fine.
Just make sure that “going pretty well” isn’t actually inertia disguised.
You accepted a job offering from Red Hat. What exactly was your role there?
I was part of the Desktop team, working together with some of the greatest developers in the GNOME community. Specifically, I was improving the Wacom tablets support in GNOME (particularly the Control Center and Settings Daemon modules). I was correcting issues, working with the designers to develop new features, in the end, trying to make things better for the user.
Did the development of Skeltrack played any role in working for Red Hat? Where there any plans of further improving and developing the abilities of the skeletal tracking library inside the Gnome desktop environment?
I think that my work in GNOME related technologies, like Skeltrack and others, was very important in being hired by Red Hat. As to whether there were plans for improving Skeltrack inside the desktop team — there weren’t. However, inside the team, we are encouraged to have new ideas and ways of improving GNOME, so maybe I could have done something around Skeltrack if I stayed longer.
What “top secrets” can you share with us about the future of Gnome development?
I don’t have any top secrets that I can share with you because, as you might know, the team works in a pretty open way and with other developers outside Red Hat. The code, design, discussions, everything can be followed through the usual channels (GNOME Live, IRC and Bugzilla).
My typical work day would consist of, besides coding, discussing with designers and other programmers on IRC and Bugzilla. Of course the team also takes care of the GNOME integration in RHEL but Red Hat tries to make things as transparent and open as possible — that is one of the things that I loved about working for the company.
Did you like version 3.10 of Gnome? What do you think is left for Gnome to do in order to reach the point of being “complete” for most people out there?
I always said that, in my opinion, some parts of GNOME 3.0 had to be improved (for example, the notifications area). That’s only normal when you have a newly developed desktop with new concepts given to you “at once” but the improvements since the 3.0 version have been huge. I was already pretty happy with the improvements 3.8 brought and I think 3.10 is another step in the good direction.
About what needs to be done to reach the point that you mean, first you have to define what means “most people”. I think it would be great if the GNOME desktop had a way to check how well features work for users but this is not as easy to do for a Free Software project as it is for a company. Putting it simple and vague, the best way would be to have a clear target user and to accept that not every critique by users is a rant and that not every change by the designers is a mindless one.
Working for Red Hat didn’t last long as you were accepted to work in CERN during this September. What is the job of a free-software engineer in the European Organization for Nuclear Research?
CERN has many different job positions related to Free Software. Those vary from sysadmins or systems integration to more “traditional” programming roles. I am currently working in the distributed storage systems team, which deals with the storage of the data that the LHC and the experiments produce (during 2012, the LHC generated 30 PB). This is a bit out of my comfort zone but that’s why it’s called a challenge :)

Guide to CERN Computing Center


CERN likes to distribute material under Creative Commons licence and use free software here and there, but how important is FOSS for organazations and research centers like CERN, and what percentage of the tools are actually free and open?
CERN is very related to FOSS and contributes to many important projects like OpenStack or Puppet. Let’s not forget that the World Wide Web was invented here and if it weren’t open, we wouldn’t have the industry around it that we have now.
I think there is no strict rule but there is an effort to release software that is made at CERN under a Free Software License. For instance, the project where I am working now, EOS, is released under GPL 3.
CERN is also behind important efforts of designing and promoting Open Hardware, like the CERN Open Hardware License. I personally think this is how international organizations, especially those supported by public funds, should be. After all, things paid by taxes money should be as open and usable as possible, and what better way to do that than releasing software under a Free Software license?
Higgs boson was tentatively confirmed to exist a few months ago. How long before we can say for sure?
Honestly, I am not a physicist so I cannot elaborate on this, however, I think that the level of certainty in which they found the particle means that assuming it exists is correct (that’s why there was all the noise).
What will be the next main scientific step for CERN after the confirmation of the Higgs boson existence?
I don’t know what the next big thing at CERN will be specifically, although the confirmation of the Higgs boson might open the possibility for doing other experiments. There are also a number of experiments that aren’t related to the Higgs boson. Just about a month ago, the CLOUD experiment made important discoveries related to amines and aerosols which might potentially be used to cool down the climate and hence reduce global warming.
I know it is impossible to answer this one, but I am sure a lot of people are asking CERN employees what do you suppose to be the daily life benefits of the Higgs boson discovery in the next 5-10 years? Do you ever wish for, or imagine anything?
I understand the question. I don’t really have a better answer than: who knows…
The thing about “playing” with physics at this level is that the benefits or applications in the future might be invaluable. Take the example of thermodynamics, in the early days of the field, it could hardly be applied to the 17th century every day life, but where would we be without it?
Apart from the potential applicability of a discovery like the Higgs boson, there are many byproducts which have been discovered or created at CERN, which are already improving our lives. Besides the already mentioned example of the WWW, you also have advances made by CERN which are nowadays used in the diagnosis and treatment of cancer (like the technologies used in Computed Tomography machines).
What is the most exciting thing you can share with us from your short experience from working in CERN?
There are many cool things at CERN! Knowing that my code will help manage the data that comes out of such unique machines is great! At some point the data reading in the network reached 32 GB/s…
Another great thing is that it is very multicultural, with people not only from Europe (as some might think) but from all over the world, and I love working in such an environment.
Overall, it makes me happy knowing that I am contributing a tiny bit to help solving the question of how the Universe was created.

That was great, thanks for sharing your experience and your opinion with us Joaquim!

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  • ScionicSpectre

    Good interview- nice to know more about all of these topics, and his balanced opinion on GNOME itself. It only makes it more obvious how out of hand peoples’ emotions have become about desktop software lately. I’m glad to see more people are getting past the trivial bickering and focusing on something useful.

  • HugoTrip

    Sorry this not a comment on the interview, but I didn’t find another way to contact you (your forums are totally spammed) : It took me a month to realize that I hadn’t any news of you because your RSS Feed is broken, at least with liferea 1.8.15 because there are 6 blank lines before XML declaration init, instead of zero. Apparently they’re caused by a plugin, a
    theme, and/or a configuration file (more details at, and it seems that this link can provide you a fix :
    thanks for your attention, and hoping to see you soon back on my newsreader…

    • mia

      Same problem here… Even Firefox gives an Error Message, when you go on …please fix it.

    • WBTMagnum

      Same here. Feed is not working in Thunderbird either.