Jannis Pohlmann Personal website


I am an open source enthusiast, student and musician from Lübeck, Germany. In my free time I enjoy hacking on Xfce and Lunar Linux. I've been a member of both teams since about 2005. Besides developing software, I love to listen to and play music (Guitar, Bass and Drums) and hang out with friends.

Contact me via jannis@xfce.org. My public PGP key is 0x354AFBA6. You can download it from here.

My CV is also available for download.

Tag - travelling

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Monday, January 10 2011

Attending FOSDEM 2011

I'm going to FOSDEM, the Free and Open
Source Software Developers' European Meeting

Today Nick and I booked hotel rooms for FOSDEM so now it’s official that the two of us will be there. I’m very much looking forward to it and I’m hoping to meet some of you at the FOSDEM Beer Event on Friday! Still need to think about a way to make ourselves recognizable as Xfce folks though.

If you are planning to attend and would like to meet any of the Xfce folks, please add your name in the wiki:


We haven’t decided where and when to meet on Saturday and Sunday but I’m sure we will find something. Stay tuned for additional announcements on this weblog.

In addition to celebrating the 4.8 release of Xfce which is scheduled for next weekend, one of our goals for FOSDEM 2011 will be to sign the papers for registering the Xfce Foundation e.V. in Germany. The details of this still need to be worked out, however. I’ll keep you posted about this as well.

If you would like to talk to me about things other than Xfce, please drop me a mail and I’m sure we can arrange something.

Friday, June 5 2009

News Update

A lot of things are going on lately and it turns out I'm way to busy to update my weblog on a regular basis. So, this is just a short post to keep you all updated.

Last two weeks

  • I took a new student job at the university, at the Institute of Theoretical Computer Science, which I love most. I'll be working on haplotyping algorithms.
  • I went to Barcelona and had a great time at the Ubuntu Developer Summit overall. Stephan and I were very productive. One evening during dinner we discussed our development and release process and later started writing it down. The result is a beautiful document that still needs a bit of polishing. I hope it'll serve as a good foundation for the development and release process of Xfce in the future. Several others commented on it and it looks like we'll give the proposed concept a shot after we've switched to git and all that.
  • Even though the week in Barcelona was great for Xfce, I was disappointed with how it went with regards to the cooperation between Xubuntu and Xfce. I talked it through with Stephan and after I got back, I resigned from my position as the Xubuntu Xfce4 Liaison.

At the moment

  • I've started to implement the so-called thumbnail management D-Bus specification. My implementation is called Tumbler and it will hopefully start serving thumbnails for other apps soon. I'm planning to use it in Thunar, Stephan has expressed interest in using it in Ristretto and when discussing the specification and the existing hildon-thumbnail implementation, Philip van Hoof told me that Hildon/Nokia might be interested in dropping hildon-thumbnail in favor of Tumbler if it's flexible enough. I'm working on it as much as I can and I'm hoping to do a release within the next few weeks.
  • I'm still working on the Transifex installation for Xfce. It's already running but I still need to import all the projects, releases and of course create accounts for maintainers automatically.
  • The migration of Xfce to Git is still work in progress. Brian has most of the repository issues sorted out and is now waiting for me to finish the commit mail script. I have two or three possible implementations lying around but I need to have a look at that again.
  • Jim needs the documentation repository next week, so I'm about to set it up.
  • Our Buildbot server has arrived in Sweden. Today I set up the firewall. Samual is taking care of setting up the Buildbot host VM and other things. We're considering to move a lot of the services not related to development (like the Xfce websites) into separate VMs on that server too, in order to make the current server a development-only machine.

Besides that I'm trying to catch up with the work and personal stuff that piled up while I was away last week. And I really should go and sleep.

Sunday, May 24 2009

Trip to Barcelona

Tomorrow afternoon I'll be travelling to Barcelona, where I'm going to spend the week surrounded by hackers from all over the world planning the next release of Ubuntu. I'll meet up with Stephan, Cody, Michael and Steve there to improve Xubuntu but I'll hopefully also run into a few other familiar faces.

During the week I'll do my best in setting up the new Xfce documentation repository based on the discussions we had over the last few weeks. I'll also try to cook up Lunar Linux modules for Transifex so that we'll have it up and running as soon as we switch our repositories over to Git. These are my goals - let's see how far I can get.

I'm hoping for a few very nice couple of days. I've never been south of Germany and it's my first time in Spain ever. As a fortunate coincidence, there's the Champions League final Barcelona vs. Manchester United on Wednesday. Not that I'm much of football fan ... but I like it when people go crazy.

Thursday, February 12 2009

Xfce at FOSDEM 2009

FOSDEM is over and it was a blast! Finally, after about four years, the team met again. It was the first time for me and it was great to meet them all in person. Olivier, Yves-Alexis, Nick and I stayed at the same hotel. Stephan stayed in Gent and the others spread over several other hotels in Brussels.


I arrived early on Friday and relaxed in the hotel room for a while, going through my slides and listening to a couple having sex next door for hours. If you’re able to count the orgasms then it’s definitely too loud. So I left the hotel and walked around in the inner city of Brussels for a while until Yves-Alexis, and shortly after that, Nick and Stephan arrived. We had a few beers at a bar around the corner and later went to for Pasta and Pizza in an Italian restaurant close to the hotel where Jens joined us. After that we went to the FOSDEM beer event and stayed there until half past midnight, only interrupted by the arrival of Olivier whom we had to take to the hotel. The beer was nice and since the place was so crowded we had a hard time understanding each other … but we somehow managed it.


We got up at around 7am the next morning and of course the beer from the evening before didn’t really make things better. The nice thing about the hotel (Hotel Du Congres by the way) was that there was free breakfast included though. It was rather basic but it did it’s job. Shortly after that we left for FOSDEM. We arrived in time for the keynotes and met Jean-François and Maximilian on our way to Janson (the large auditorium). Later we went for some french fries and mainly spent our time in the X.org devroom. Some of us went to the LXDE lightning talk and were quite amused by their claim that LXDE is better than Xfce (which is denied by the guys at LXDE, so they might not actually have said that … what does better mean anyway?) and the huge number of slides showing photos of their team at different conferences. Later that day we went to a restaurant called Big Mama in the very heart of Brussels were we had a beer and nice food. Everyone went to bed afterwards, except Nick, who kept hacking on the panel.


Sunday was a big day for me - I had a talk about Xfce 4.6 and the future of Xfce scheduled at 11am. I didn’t really sleep well and was nervous the entire morning. It didn’t get any better when I had finally booted up my laptop and the microphone was turned on. I don’t know how long I talked but I have the feeling that I literally speed-talked through the slides. I forgot a few things I would’ve loved to mention but all in all I think it was ok. There were quite a few sceptical faces in the audience but also a few who looked very pleased by the features and plans I presented them. I definitely think it was ok for my first talk in English at a big conference but I know I can do better. So I’d be absolutely happy to do that again next year!

I felt very relieved afterwards. We then went out to take a few group pictures (the following one was shot by Jens). In the meantime, Samuel and Jelle de Jong had joined us (I have no idea where Jelle went afterwards, but Samuel stayed with us for the rest of the day).

Xfce group picture at FOSDEM 2009

After that we want back to one of the devrooms until Maximilian came back from his car with a number of sandwiches he had bought on the way. We had a beer at the FOSDEM bar, ate our sandwiches and then went back to the cross desktop room for Stephan’s talk about Xfce as a platform. I think he did a good job overall, especially considering that he had just finished his slides the night before. I would’ve loved to see more about how to use the different libraries and maybe more details about our plugin APIs but he covered a few very important things about Xfconf.

After that we had another beer at the bar and went to the last talks in Janson. Samuel dropped his full beer, I accidently kicked my empty one and Olivier and I left early for the FOSDEM bus back to Brussels-South. I managed to catch an earlier train to the airport, had a short flight, then had to wait for the bus from Hamburg to Lübeck for 90 minutes and finally arrived at around half past midnight.

I think it was a lot of fun and I’ll definitely go to FOSDEM again. It was nice to put a face to all the names of people I’ve been working with over the last few years. Thanks to everyone I met there, it was a real pleasure! Hope to see you all again! Thanks to all the people who went to our talks (oh, and to that guy who wanted that picture of him and me - could you send it to me please?) and asked questions (“Has the Xfce team ever thought about participating in Google SoC?”, “How good is the relationship of Xfce with Xubuntu?”, “Are you still aiming to be lightweight?” amongst others). It was also great to see several packagers, like Mark from Foresight, Landry from OpenBSD and Christoph from Fedora.

As I’ve mentioned before, I would really like to talk at conferences again. It’s a challenge but definitely a nice one. If you know any that could be interesting for Xfce, please let me know!

Oh, and by the way, if you’ve taken any pictures of us at FOSDEM, please let us know!

Wednesday, December 24 2008

Topics raised at UDS

Ok, this post is long overdue and has been around as a draft for more than a week now, so here it is. As readers of this weblog already know, I was at the Ubuntu Developer Summit from December 8th to 12th. We had quite a few discussions on topics I'm interested in outside the scope of the official sessions held at UDS. Let me just list them here in random order:


Arnaud Quette told me about Buildbot which can be used to test your repository for compilation errors on various systems. I suppose it can be a real time saver if you want your project to compile on a variety of distributions and UNIX flavors and want immediate response as to whether compilation is going to succeed on these. That way you don't have to wait for packagers and users to report compilation errors back to you and don't have to enter that typical ping pong developer-reporter dialog. Buildbot not only catches compilation errors but is also capable of sending notification emails and provides detailed information about the compile log and so on. It's implemented based on a server/client concept where each client tests compilation on one system and the server collects data from the clients. By using virtualization you can set up server and clients on the same machine. This would be very nice to have for Xfce but I suppose it would require another dedicated server just for running all these compilations. If anyone is interested in looking in to that, I'd be happy to establish contact to someone from Buildbot to provide you with more information. As a funny coincidence, Frédéric Péters recently announced build.gnome.org which is a great example of Buildbot usage.

Thunar and GIO

I talked to Christian Kellner about GIO/GVfs a bit in order to get information on how remote/virtual filesystems work. One thing I've thought about is how to allow for a list of user-defined remote/virtual filesystems which show up in the side pane of Thunar. There are different approaches to that. One is to use bookmarks which seems to be what, according to Christian, Nautilus does right now. While this seems to work quite well it seems to confuse users a bit. Personally, I'd like to see them separated from bookmarks. There has been a proposal for Nautilus to make the side pane look better by using sections. One thing I could imagine would be to have a "Virtual Volumes" section listing the user-defined filesystems and provide some sort of GUI for creating/removing/editing these. From what I've heard there also is a third approach, which is to make remote filesystems to appear as fake volumes in HAL or DeviceKit. I'll have to look into that in order to decide what the best way to go is, I guess.

PulseAudio and GStreamer

PulseAudio and GStreamer: We discussed the limited PulseAudio backend for GStreamer in a group of up to five people and agreed that it really needs improvement (as in more tracks have to be added to the GstMixer interface) if we don't want users to be able to control PulseAudio through the mixer applications they know. PulseAudio-specific applications like pavucontrol are not really what we want them to use.

Xubuntu Remix for Netbooks

During one of the Xubuntu sessions I talked to a member of the Ubuntu Mobile team about Xfce in general, the modularity of Xfce and the dependencies it has. He seemed to be very interested in it but he was also worried about Xfce becoming less lightweight, eating up more memory and disk space. It wasn't the first time during UDS that someone mentioned LXDE and asked me about my opinion on it. Two main reasons for Xfce being lightweight always were the small number of dependencies and applications which you could call the Xfce stack. With more and more applications and libraries being added, Xfce naturally feel less lightweight, even if these applications are not considered a part of the core desktop. You always have to keep that in mind. It seems like the high modularity of Xfce compensates parts of that and is why people are interested in Xfce in the context of mobile devices. Despite being modular and somewhat lightweight, Xfce also has improved in terms of user experience lately. I think we can push this even further. Giving accessibility more attention might also be worth considering. Usability is something I don't really see in LXDE (yet). That's what I usually tell people if they ask me for my opinion on it.

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