The German Linux Magazine runs a sponsored an "Open Source Lounge" at CeBIT each year. Last year I put in a proposal for DAViCal and it got accepted! With some airfare support from InternetNZ I got to showcase my Free Software project at the largest IT trade fair in the world.If you have an open source project to promote I can't recommend this highly enough. Below is a review of my experience at CeBIT early this year. This is long overdue for posting, and I'm prompted now because submissions are now open for the Open Source Project Lounge at CeBIT in 2012. Apply now.The German Linux Magazine runs a sponsored an "Open Source Lounge" at CeBIT each year. Last year I put in a proposal for DAViCal and it got accepted! With some airfare support from InternetNZ I got to showcase my Free Software project at the largest IT trade fair in the world. If you have an open source project to promote I can't recommend this highly enough. Below is a review of my experience at CeBIT early this year. This is long overdue for posting, and I'm prompted now because submissions are now open for the Open Source Project Lounge at CeBIT in 2012. Apply now. DAViCal at CeBIT 2011 CeBIT in Hannover is said to be the largest trade fair in the world, attracting over 300,000 visitors during it's five days. Late last year a DAViCal user in Germany suggested that I apply for a free booth for DAViCal in the Linux New Media Open Source Project Lounge . When DAViCal was accepted, I realised I needed some funding to help me travel around the world to attend, so I applied for a grant from InternetNZ who were kind enough to agree to cover part of my travel costs, and I was on my way. Germany in March is cold, especially for me coming from Summer! My travel allowed for a couple of days in Germany before CeBIT because that was when I could get the cheapest flights, and I wanted to have a little time to recover from the journey. Everyone had warned me to pack my winter woollies, and they were definitely needed! I stayed with a friend in Hamburg for two days and on the the second day we walked through the frozen park, past the frozen lake and over the frozen streams to see the Attraktor Hackerspace in Hamburg Nord where the CCC also hold their meetings a very impressive hackerspace in a repurposed bank (including the vault :-) with several separated areas for talks, meetings and workplaces. The day before CeBIT I travelled to Hannover to take a look at my booth space, fetch exhibitor passes for myself and volunteers and generally prepare to do battle with the crowds. The following day the fair started and it was up at 6:30 to get ready and catch the 7:38 train out to the fairgrounds. Although the fair opens at 9:00 there was always something to do between eight o'clock or so when I arrived at my booth and when the attendees started wandering past.
I was fortunate to have two volunteers for my booth who were there all week, as well as a couple more who turned up on the first two days. Not only did this mean that I got to spend a few hours during the week actually wandering the fairgrounds, but that I had some knowledgeable native german speakers for the occasional visitor who could not speak English. DAViCal has been translated into a dozen languages, and there had been some extra work put in to update the German translation before CeBIT also. As well as showing DAViCal, I was also able to demonstrate a new project at the fair which was aCal - a CalDAV Calendar Client for Android which I had released into the market just a few days beforehand for a token sum (it is licensed GPL v3 or later and the source code is available on gitorious.org). Having the smartphone devices available was great for giving live demonstrations, and I used the timetable for events at the Open Source Forum across the aisle from the Open Source Lounge to populate a calendar that we shared among a variety of devices. The first day was really the calm before the storm, and we saw lots of people asking what we were about, and had some good conversations with people wanting to know more, or telling us they used the software and were very happy with it.
CeBIT closes the gates at 18:00 with the visitor supply drying up pretty quickly around then and the secret lives of the exhibitors are revealed with people starting to relax and joke, and beer or wine starting to come out and some booth parties kicking off... if you have the stamina! I didn't, so it was off back to the train, to Hildesheim, to dinner and to bed. That first day blurred into the next, and the next and by Friday I was starting to lose my voice with all the talking I had been doing. I was visited by a chap from Posnan University who are a DAViCal user and he invited me down to the Polish stand to tell me about what they do there, and he agreed that they would love to help get the Polish translation improved. Another DAViCal user turned up with some bavarian wheat beer and a special beer glass for it by way of thanks. In some spare moments I fixed a bug in aCal's handling of character sets and uploaded a new version, so that we could use umlauts in events. Many people came past to talk to us, some of whom want to help with them project or have ideas for interesting things to do with DAViCal, some were already users of DAViCal and some went away thinking that they would be in the future. The last day of CeBIT is a little different: it's a Saturday and the doors are opened to the public and the minimum age is lowered to allow children to attend the event. I had been warned that this day is a madhouse, and it did indeed seem to be so for many booths. For DAViCal it was probably quieter than the day before, I think perhaps because calendar server software is inherently less sexy than many of the other things on display. We still had plenty of great discussions with interested people nonetheless and to be honest I was fairly happy to be spared the further exhaustion that had been threatened. Sunday was spent recuperating: discovering that Hildesheim has a great little restaurant that does traditional german pancakes for breakfast and then wandering around the small city soaking in the sunshine that I'd seen through the windows outside all week. On Monday I caught the train to M nchengladbach to meet with an organisation that might provide support for DAViCal in Germany, but who hadn't been able to come to the fair to see me due to illness. I was encouraged to spend the night in Aachen a beautiful little city , which I did, arriving around sunset and I spent a couple more days before flying home being intensely antisocial to recover from the furious week beforehand. Is CeBIT worth it? CeBIT seemed to me to be quite a different business model, or perhaps on a different scale. I've seen trade fairs in New Zealand for other purposes, but not to showcase software and services in quite this way. To give an idea of it's scale, consider that I had a tiny booth in a hall that was probably four times the size of the TSB Arena, and CeBIT included around 20 such buildings , packed with exhibitors, with free buses to get around the campus, acres of multi-storey parking buildings, two train stations, and so on. The scale of the event is incredible. As a result of this scale, CeBIT boasts impressive visitor numbers, and while a visitor will usually attend with a specific area of interest in relation to their business they will also wander the fair to see other areas of more personal interest, or just to see what is around. Open Source is a specific area of interest to a significant percentage of business in Germany, and Deutsche Messe, the fair operators, recognise the value of having an open source area as a draw for visitors, with the primary open source area placed in Hall 2, directly off the main north entrance. Within the open source area, the Open Source Project Lounge , where DAViCal was located, is a series of booths sponsored by Linux New Media AG. Projects in the Open Source Lounge are selected by a jury of Linux New Media, Deutsche Messe and several community advisors, so as such there is a range of interesting projects on show and the draw of any given project has a flow-on effect to the others. As an example, at one point while briefly minding the adjacent stand for the OpenEmbedded project I was unable to help an inquiring visitor, but I was able to talk about DAViCal with him until the exhibitor returned to answer his question. His interest in DAViCal was definitely increased in this process, and I'm sure that many people came into our area of the lounge attracted by a specific exhibitor and moving on to see some of the others. Outside of this association with open source, however, CeBIT offers something which general free software events cannot: an association with mainstream software and services. This presentation of Open Source alongside IBM, SAP, HP, Oracle, Software AG, Apple, Microsoft and so forth makes inclusion at this event particularly valuable. Free software solutions can have good brand recognition within the open ecosystem itself and yet be practically unheard of outside it. Most traditional methods of communication with suppliers don't work well with Open Source projects: a request for proposal will sail silently by, unless noted by a related commercial entity. In general there is no sales department, and marketing is frequently a desultory hit or miss affair. The fair is different. The fair is about talking with people. While there is still plenty of collateral marketing with brochures, signs, presentations and giveaway knick-knacks those things are just there to bring people into range: the real action happens when you engage a person in conversation, and at that point a humble free software project can be on an equal footing with a larger booth staffed with eager young salesmen. Of course there are a number of places where free software can get a booth. Linuxtag is a German example where there are many booths for free software projects, linux.conf.au also offers booths to free software projects during it's more outreach Open Day and software freedom day events happen all around the world where booths are available, but the audience arriving at these events are all largely pre-sold on openness and free software. So in presenting this broad blend of people, in a way in which free software projects can present on a roughly equal footing with their commercial brethren, CeBIT is an opportunity not to be missed. The numbers speak for themselves, too: traffic to the DAViCal websites has increased by about 50% around CeBIT with 25% coming from Germany, but significant increases also from France, Netherlands, Italy, Switzerland and Poland. Traffic to the DAViCal wiki has doubled over the last 12 months in a steady increase to around 200,000 page views each month. This sudden increase to around 10000/day in March, with some days during CeBIT peaking at over 20000/day The Future I won't be returning to CeBIT to represent DAViCal in Hannover next year as the sponsored booth is pretty much a one-time thing and the costs involved in purchasing a booth for attendance at the fair are significant (around NZD$15000 for a small 3m x 2m stall). It's possible that I will return next year in a different capacity, as one of the larger stand organisers has confidentially indicated he will invite me to attend as part of an Open Source Apps area that he is considering running on his stand, somewhat along the lines of the Open Source Lounge . Time will tell, I guess, but if invited I think I would definitely go for that. I will definitely be suggesting to a few specific free software projects that they should apply for the Linux New Media opportunity when it comes around again. Koha is one project that immediately springs to mind, but of course there are many, many worthy free software projects and this opportunity seems to be little-understood outside of Germany. If I do convince a project to apply, and they are successful, I will also try and give them some assistance and background knowledge to understand the fair, and how best they can take advantage of the opportunity it offers. Some basic tips would be:

• Book accommodation early, a small apartment or B&B is good. CeBIT accommodation prices are exceptionally high 3 or more times normal rates. There are companies that specialise in renting apartments for the week of CeBIT which are more reasonably priced.
• The fair is in Hannover , except that really it is some distance to the southeast. Exhibitors tickets provide free transport within greater Hannover for the whole week, so you don't actually need to be that close. Options like Hildesheim, a city of some 120k people south of Hannover (where I stayed), are also good although they add a small transport cost.
• Have a pop-up banner for your project.
• Develop a slideshow which tells people about your project and which can just be left running on a larger screen.
• Have a flyer you can hand out to interested people.
• Get at least one committed person to assist on the stand for the whole week.
• Get some more volunteers to assist on the stand for one day each.
• Pace yourself: get to bed early and try not to overdo the partying it's a long week!
• If you want to take a look around the fair don't wait until Friday or Saturday do it on Thursday or earlier.

and finally... I would like to express my appreciation to InternetNZ for the grant to partially cover my travel costs to Hannover, making my attendance at this outstanding event much more achievable. My thanks also to Britta Wulfling who supported all of the projects in the Open Source Lounge. My friends Alexander & Meike in Hildesheim who supplied somewhere for me to recuperate, and accompanied me to the fair every day to run the Debian booth. Thanks also, of course, to the German Linux Magazine for selecting DAViCal for a free booth, and to Benny who pointed the opportunity out, encouraged me to apply, and came along and helped out for the whole week.

I think I'm currently supposed to be out buying a TV at the moment. Or something else expensive. Instead I'm lying on the sofa listening to Whale and drinking tea. That's much better in my opinion, but it reminded me that I hadn't mentioned that I bought a projector. I had the loan of a projector for a while when I was in Belfast. It was a huge thing that made a lot of noise, but was pretty cool for watching films with. When I moved to the US I decided not to bother with a TV to start with - using my laptop did just fine for most things. Except films. They really benefit from a bigger screen. Especially if you want to watch them with someone else. So I started looking at pico projectors, because I wanted something small and cute that I could throw in a bag with my tiny laptop. At the time the best the pico projectors could do was 840x480, which I felt wasn't really that great. However back in January TI announced their DLP Pico HD chipset, offering a resolution 1280x800. I kept a look out for projectors using this to appear, and eventually, in July, Amazon claimed to have availability of the Vivtek Qumi. So I bought one. And I'm very happy with it. I'm not a heavy user, and there are some niggles, but it's small and does exactly what I want. In low light conditions it'll happily throw an image all the way across the room, which is more than it's rated at. There's a mini-HDMI connector on the back, so it's a doddle to plug it into my laptop using the supplied HDMI to mini-HDMI cable. The laptop auto-detects the device and extends the desktop appropriate, as you'd expect. It'll also do media playback itself - there's a USB host port and a micro SD slot on the back. This works ok, and the included remote means you can easily set the projector somewhere above your head and still be able to easily control it. Unfortunately the built in speakers are fairly useless. There's a 3.5mm socket for external speakers, but having to plug something else in detracts from the convenience factor of the built-in media player. Also my unit had the power switch installed upside down (the little red line indicating the power is on actually shows up when it's off), but that's the only complaint I've got about the build quality. There's a little neoprene case to store the thing in as well. So, er, yeah. I think I can continue to make do without a normal TV for a while longer and avoid the nightmare that I suspect are the shops on Black Friday.

Andrew Cowie blogs about 'A good GNOME 3 Experience'. He writes

I think it s a bit odd not to expect that something that was widely advertised as being such a different user experience is different.

and

if they had gone and bought an Apple laptop with Mac OS X on it they would be perfectly reasonably working through learning how to use a new Desktop and not complaining about it at all. But here we are admonishing the GNOME hackers had the temerity to do something new and different.

I think Andrew's phrasing here is a bit disingeneous. Or perhaps he genuinely mistakes the frustration that has been felt by GNOME 3. I don't want to whine on too much, so I'll try to get this out of the way in one paragraph. F/OSS users are members of a community. There is inevitably a wall between the majority of community members and the blessed: the decision makers, the developers. The art of maintaining a good community is partly to do with making this wall as invisible as possible: encouraging participation, lowering the barrier for contributions; welcoming feedback; etc.1. The GNOME community have invested a lot into the GNOME 2 way of doing things, and GNOME 3, by breaking away from that so fundamentally, has devalued the community's investment. It screams: we don't want your panel widgets! We don't want your themes! Your working practices are wrong: this is the right way! GNOME 3 is opinionated software, and it's opinion differs from a large body of the GNOME community. The result? resentment. Remember: GNOME 3 is not just something new: it's the abrupt termination of something old, tried and tested. and hopefully that's the last time I need to vent about my GNOME 3 frustration. It's hear to stay, the question for the frustrated is: are you? Moving on Andrew goes on to recommend:

One thing I do recommend is mapping (say) CapsLock as an additional Hyper You do the mapping in: System Settings Keyboard Layout Layout tab Options..

I used to do this with GNOME 2, but I couldn't find how to do it on GNOME 3. Andrew's post gave me the important hint that it was still possible, but the precise location doesn't match: On my Fedora 16 / GNOME 3.2 system, it's System Settings Region and Language Layouts Options ". This is especially useful on my beloved UltraNav keyboard which lacks the Windows 95 keys. Sadly it does not work very well through various remote desktop tools: I get an inconsistent capslock state within VMs connected to via VNC. rdesktop seems ok.

It s been one year since the first People behind Debian interview. For this special occasion, I wanted a special guest and I m happy that our Debian Project Leader (DPL) Stefano Zacchiroli accepted my invitation. He has a difficult role in the community, but he s doing a really great job of it. He s a great mediator in difficult situations, but he s also opinionated and can push a discussion towards a conclusion. Read on to learn how he became a Debian developer and later DPL, what he s excited about in the next Debian release, and much more. Raphael: Who are you? Stefano: I m Stefano Zacchiroli, but I prefer to be called Zack, both on the Internet and in real life. I m 32, Italian, emigrated to France about 4 years ago. I live in Paris, and I find it to be one of the most gorgeous and exciting cities in the world. As my day job I m a Computer Science researcher and teacher at University Paris Diderot and IRILL. In my copious free time I contribute to Debian, and I m firmly convinced that doing so is an effective way to help the cause of Free Software. Besides, I find it to be a lot of fun! Raphael: How did you start contributing to Debian? Stefano: Flash back to 1999, when I was a 2nd year student in Computer Science at the University of Bologna. Back then in Italy it was uncommon for young geeks to get exposed to Free Software: Internet was way less pervasive than today and most computer magazines didn t pay much attention to GNU/Linux. Luckily for me, the professor in charge of the student lab was a Free Software enthusiast and all students machines there were running Debian. Not only that, but there was also a student program that allowed volunteers to become sysadmins after having shown their skills and convinced the director they were trustworthy. Becoming one of those volunteer Debian admins quickly became one of my top objectives for the year, and that is were I ve learned using Debian. The year after that, I got in touch with a research group that was to become the happy bunch of hackers with whom I would have done both my master and PhD theses. They were designing a new proof assistant. Most of the development was in OCaml and happened on Debian. OCaml was available in Debian, but many of the libraries we needed were not. So I approached the Debian OCaml Team offering to help. Before I realize what was going on I was (co-)maintainer of tens of OCaml-related packages. At some point I got told I think you should apply as a Debian Developer . So I did and in a couple of months I went through the New Member (NM) process, that was back then in its infancy. I still remember my happiness while reading the account created mail, the day after my 22nd birthday. I know the NM process went through some bad publicity in the past, but I m happy to see that nowadays the process can be as swift as it has been for me 10 years ago. Raphael: It s your second year as Debian Project Leader (DPL). Are you feeling more productive in the role? Do you fear to burn out? Stefano: I m feeling way more productive, no doubts. The task of the Debian Project Leader is not necessarily difficult, but it is a complex and scarcely documented one. It is also profoundly different from any other task that Debian people usually work on, so that experience doesn t help much in getting started. Before becoming effective as DPL one needs to get to know many people and mechanisms he is not familiar with. More importantly, one needs to set up a personal work-flow that allows to keep up with day-to-day DPL tasks (which are aplenty) as well as with urgencies (that tend to pop-up in the leader@debian.org INBOX at the least convenient time). Finally, one also needs to do proper traffic shaping and always retain enough motivation bandwidth to keep the Project informed about what is going on in DPL-land. Finding the right balance among all these ingredients can take some time. Once one is past it, everything goes way more smoothly. The above is why I m constantly encouraging people interested in running for DPL in the future to reach out to me and work on some tasks of the current DPL s TODO list. I swear it is not just a cheap attempt at slavery!. It is rather an attempt at DPL mentoring that could be beneficial: both to give future candidates more awareness of the task, and to reduce the potential downtime when handing over from one DPL to the next. Regarding burn out, I don t feel prone to its risk these days. If I look back, I can say that my contributions as DPL have been pretty constant in volume over time; my enthusiasm for the task, if anything, is on the rise. The effectiveness of my contributions as DPL are, on the other hand, not mine to judge. Raphael: If you had to single out two achievements where you were involved as DPL, what would they be? Stefano: I d go for the following two, in no particular order:

• Dialogue with derivatives. When I became DPL ~1.5 years ago the situation on that front was pretty dire. In the specific case of Ubuntu, by far the most successful and customized of all Debian derivatives, I remember being scared of raising the topic of collaboration with them on mailing lists. More generally, we had no specific initiatives to foster technical collaboration with and among derivatives. A huge potential of (forwarded) contributions to Debian was being wasted. Today things look much better, as I ve documented in recent talks at DebConf11 and UDS-P. The amount of forwarded patches we receive from downstream is at its maximum and many people who apply to become Debian Developers come from derivatives. Conflict situations still exist, for good reasons that we still have to either fix or figure out entirely. But I m positive we re on the right track.

  The amount of forwarded patches we receive from downstream is at its maximum

  This is by far not an achievement of mine alone. In particular, many of the activity of the Derivatives Front Desk have been organized by other enthusiastic volunteers. But I ve done my part, especially in breaking the ice and in proposing a vision of Free Software distribution where all distros play a role and are welcome to join the game, as long as they give back and give credit to their respective upstreams.
• Process membership. I m proud of having promoted the general resolution (GR) that has clarified (and advertised to the world) that Debian welcomes all kind of contributions, and that they all equally matter to become proper members of the Project. I notice only now while writing this that the GR title, traditionally chosen by the secretary, was Debian Project Members . That choice harmonically closes the circle with the recent renaming of the NM process to New Member process. Today, we have several project members (AKA Debian Developers ) that are active citizen of Debian with voting rights, even though they take care of tasks other than packaging. Anyone can become a Debian citizen, as long as they are ready to abide by Debian s values, have a track record of verifiable contributions to Debian, and are committed to keep them coming in the future.

  We have several project members that [ ] take care of tasks other than packaging.

  Once gain, this is by far not an achievement of mine alone, very little project-wide achievements are. DAM has helped a lot and support from the project as a whole has been immense.

OK, let me cheat and add a third one I m also proud of having been able to report to the Project my whereabouts as DPL, thoroughly and periodically, since the very beginning is first term. People annoyed by my reporting logorrhea now have all my sympathies. Raphael: Among the possible new features of Debian Wheezy, which one gets you excited most? Stefano: It s multi-arch, no doubt. Even though it is not a directly user visible change, it s a very far reaching one. It is also one of those changes that make me feel that moment of truth of coders, when you realize you are finally doing the right thing and ditching piles of ugly hacks.

It s multi-arch [ ] you realize you are finally doing the right thing and ditching piles of ugly hacks.

Raphael: If you were not DPL and could spend all your time on Debian, what project would you do? Stefano: I would sit down and do software development for Debian. It s impressive how many important and beneficial changes for Debian could be delivered by specific software improvements in various parts of our infrastructure. We tend to attract many packagers, but not so many people willing to maintain Debian infrastructure softwares like dak, britney, debbugs, the PTS, etc. Their maintenance burden then falls on the shoulders of the respective teams which are generally very busy with other important tasks. As a project, we seem to be more appealing to packagers than to software developers. That is a pity given the amount of exciting coding tasks that are everywhere in Debian. Part of the reason we are not appealing to developers is that we are not particularly good at collecting coding tasks in a place where interested developers could easily pick them up. It also takes quite a bit of inside knowledge to spot infrastructure bugs and understand how to fix them. I long for some spare hacking time to check if I m still good enough of a coder to hunt down longstanding bugs in our infrastructure, which have ended up being my pet peeves. I d also love to dive again into RCBW. It s less committing than package maintenance, more diverse and challenging, and also an immensely useful activity to get Debian releases done. Raphael: Martin Michlmayr is worried that there is so few paid opportunities around Debian. Do you agree with his sentiment, and if yes do you have ideas on how to improve this situation? Stefano: The idealistic me wishes Debian to be a community made only of volunteers that devote their free time to the Project. Oh, and that me also wishes Debian to be competitive with similar projects, no matter how many full-time employees others have! That is coherent with a view of society where everyone has a day job, but also engages in volunteering activities ensuring that public interest is pursued by people motivated by interests other than profit. But I do realize that for Free Software to succeed companies, employees, and salaries should all have a role. I admire projects that strike a good balance between volunteer and paid work. The Linux kernel is emblematic in that respect: many developers are paid by companies that have a commercial or strategic interest in Linux. Nevertheless volunteers contributions are aplenty and the Linux community gives a convincing impression that choices are driven by the community itself (or by its benevolent dictator) without money-driven impositions.

I do realize that for Free Software to succeed companies, employees, and salaries should all have a role.

Such an ecosystem does not exist around Debian. We do have a partner program that allows for it to happen, but we have very few partners with an interest in doing distribution development work. Like Martin, I m worried by this state of affairs, because it de facto means we lag behind in terms of available people power. In a community of volunteers, that might frustrate people and that is not good. To improve over the status quo the first step is to federate together small and medium companies that have a strategic interest in Debian and listen to their needs. I m already in touch with representatives of such companies that, in many cases, already employ Debian Developers to do some distribution work in Debian. We will be soon sending out a call to reach out to more such companies, but since we are discussing this, why waiting? If some of our readers here are representative of such companies, I encourage them to get in touch with me about this. Raphael: You know that the fundraising campaign for the Debian Administrator s Handbook is on good track but the liberation of the book is not yet assured. What do you think of this project? Stefano: I m happy about the project, to the point that I ve accepted writing a testimonial for it . I m sad about the scarce availability of up to date and high quality (DFSG-)Free books about Debian and I welcome any initiative that might help closing that gap.

I m sad about the scarce availability of up to date and high quality (DFSG-)Free books about Debian.

Free Culture is a great offspring of Free Software and I m convinced we need to stand up against double standards in the two camps. Letting aside software-specific licensing details, the basic freedoms to be defended are the same. They are those freedoms that ensure that a reader is in full control of his book, pretty much as they ensure that a computer user is in full control of the software that runs on it. I m therefore proud that Debian has long resolved that the Debian Free Software Guidelines (DFSG) apply not only to software but also to books and other pieces of documentation. But the status quo implies that not only we have very few up to date, high quality books about Debian. It also implies that, at present, we have no such book that we can distribute in the Debian archive, showing off the Free Software (and Free Culture!) values we stand for.
Crowdfunding is considered to be a good mate for Free Culture, where the services model that applies to Free Software is more difficult to exploit. I so wish any luck to yours and Roland s initiative. A different matter is whether Debian, as a project, should endorse the initiative and actively campaign for it. As you know, I think it should not. While we do advertise general project donations, we don t do mission-specific fundraising campaign for Debian itself. Coherently with that, I don t think we should relay crowdfunding campaigns for 3rd parties, even when the result would be beneficial to Debian. Raphael: Is there someone in Debian that you admire for their contributions? Stefano: There are two classes of people that I particularly admire in Debian:

• Those with an uncanny ability to guide discussions towards constructive conclusions. We are lucky to have many in Debian and I admire all of them. Having to single out one I d name Russ Allbery, in honor of whom I hereby propose the periodic Russ Allbery s Distinguished Flametamer Award .
• People stepping up for responsibility roles, especially when the responsibility put them in tough spots. Release teams, ftp-masters, DSA, DAM, as well as past and present members of teams with similarly hot seats have all my admiration.

---

Thank you to Zack for the time spent answering my questions. I hope you enjoyed reading his answers as I did.

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RPostgreSQL goes back to a topic suggestion I had made for the Google Summer of Code 2008, and specifically for the R Project participation that year. And Sameer Kumar Prayaga (whom I then mentored for the project) did a fine job that summer putting together a working framework of package connecting R and the excellent PostgreSQL database system. Unfortunately, Sameer vanished once the summer was up; I heard he got himself a job a another db company. Fast-forward a few years. A caretaker group had maintained the package in the meantime, but without really writing any new code. But thanks to the tireless efforts of Tomoaki Nishiyama, who not only wrote a lot of new code addressing some of issues logged at the Google Code project page, but also stepped forward and became the new lead maintainer, things are much, much better now. The first 0.2-0 release a few weeks ago already addressed a rather large number of issues, bringing the feature set much closer to what one would expect from a feature-complete package. But one big thorn remained: builds on Windows still required a local PostgreSQL library installation as well as local compilation. And as we can tell from the mailing list(s), this is a little daunting for many potential users. But what did release 0.2-1 bring: a complete set of libpq sources so that builds on Windows no longer require presence of local PostgreSQL sources! We tested this using Uwe Ligges' excellent win-builder service for R, and after I reminded Uwe on the weekend to no longer blacklist build attempts of RPostgreSQL, we now have Windows binaries for direct installation. Just call install.packages(), and you're good to go -- much nicer! Tomoaki achieved this pretty much single-handedly, and for that reason he greatly deserves some extra praise as an unsung Open Source hero!

A few days ago, Conrad Sanderson released the first pre-release version of what will be Armadillo 2.4.*, giving it the 2.3.91 release handle. We folded this into RcppArmadillo release 0.2.30, with Romain making a few adjustments to our template structure to accomodate Conrad's underlying changes in Armadillo itself. Armadillo is a wonderfully expressive (thanks to clever modern template programming), powerful yet simple-to-use C++ library for linear algebra, making expressions in C++ as easy as writing in Matlab or R. By deploying our seamless Rcpp glue between R and C++, RcppArmadillo brings this nice C++ library to R users. The CRAN page for RcppArmadillo now lists ten packages using the RcppArmadillo package. There was also an earlier bug-fix release 0.2.29 which I had not blogged about separately. The NEWS entries summarising the changes for both are below:

0.2.30  2011-11-19
    o   Upgraded to Armadillo test release 2.3.91 "Loco Lounge Lizard (Beta 1)"
          * added shorter forms of transposes: .t() and .st()
          * added optional use of 64 bit indices, allowing matrices to have
            more than 4 billion elements
          * added experimental support for C++11 initialiser lists
          * faster pinv()
          * faster inplace transpose
          * bugfixes for handling expressions with aliasing and submatrices
          * refactored code to eliminate warnings when using the Clang C++
            compiler
          * .print_trans() and .raw_print_trans() are deprecated 
0.2.29  2011-09-01
    o   Upgraded to Armadillo release 2.2.3
          * Release fixes a speed issue in the as_scalar() function.

Courtesy of CRANberries, there are also diffstat reports for 0.2.30 relative to 0.2.29 and for 0.2.29 relative to 0.2.28. As always, more detailed information is on the RcppArmadillo page. Questions, comments etc should go to the rcpp-devel mailing list off the R-Forge page.

Starting with Fedora 16 we're installing using GPT disklabels by default, even on BIOS-based systems. This is worth noting because most BIOSes have absolutely no idea what GPT is, which you'd think would create some problems. And, unsurprisingly, it does. Shock. But let's have an overview.

GPT, or GUID Partition Table, is part of the UEFI specification. It defines a partition table format that allows up to 128 partitions per disk, with 64 bit start and end values allowing partitions up to 9.4ZB (assuming 512 byte blocks). This is great, because the existing MBR partitioning format only allows up to 2.2TB when using 512 byte blocks. But most BIOSes (and most older operating systems) don't understand GPT, so plugging in a GPT-partitioned disk would result in the system believing that the drive was uninitialised. This is avoided by specifying a protective MBR. This is a valid MBR partition table with a single partition covering the entire disk (or the first 2.2TB of the disk if it's larger than that) and the partition type set to 0xee ("GPT Protective"). GPT-unaware BIOSes and operating systems will see a partition they don't understand and simply ignore it.

But how do we boot a GPT-labelled disk with a protective MBR on a system that doesn't understand GPT? The key here is that BIOS is pretty dumb. Typically a BIOS will see a disk and just attempt to execute the code in the first sector. This MBR code knows how to do the rest of the boot, including parsing the partition table if necessary. The BIOS doesn't need to care at all.

Of course, some BIOSes choose to care. We've seen a small number of machines that, when exposed to a GPT disk, refuse to boot because they parse the MBR partition map and don't like what they see. This is typically accompanied by a message along the lines of "No operating system found". What we've found is that they're looking for a partition marked with the bootable flag, and if no partitions are marked bootable they assume that there's no OS. This is in contrast to the traditional use of the flag, which is merely a hint to the MBR as to which partition boot code it should execute.

So, should we set that flag? The UEFI specification specifically forbids it - table 15 states that the BootIndicator byte must be set to 0. Once again we're left in an unfortunate position where the specification and reality collide in an awkward way.

If this happens to you after a Fedora 16 install, you have two choices. The first is to reinstall with the "nogpt" boot argument. The installer will then set up a traditional MBR partition table. The second is to boot off a live CD and run fdisk against the boot disk. It'll give a bunch of scary warnings. Ignore them. Hit "a", then "1", then "w" to write it to disk. Things ought to work then. We'll figure out something better for F17.

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I probably don t have to present Mark Shuttleworth he was already a Debian developer when he became millionaire after having sold Thawte to Verisign in 1999. Then in 2002 he became the first African (and first Debian developer) in space. 2 years later, he found another grandiose project to pursue: bring the Microsoft monopoly to an end with a new alternative operating system named Ubuntu (see bug #1). I have met Mark during Debconf 6 in Oaxtepec (Mexico), we were both trying to find ways to enhance the collaboration between Debian and Ubuntu. The least I can say is that Mark is opinionated but any leader usually is, and in particular the self-appointed ones! Read on to discover his view on the Ubuntu-Debian relationship and much more. Raphael: Who are you? Mark: At heart I m an explorer, inventor and strategist. Change in technology, society and business is what fascinates me, and I devote almost all of my time and wealth to the catalysis of change in a direction that I hope improves society and the environment. I m 38, studied information systems and finance at the University of Cape Town. My hearts home is Cape Town, and I ve lived there and in Star City and in London, now I live in the Isle of Man with my girlfriend Claire and 14 precocious ducks. I joined Debian in around 1995 because I was helping to setup web servers for as many groups as possible, and I thought Debian s approach to packaging was very sensible but there was no package for Apache. In those days, the NM process was a little easier Raphael: What was your initial motivation when you decided to create Ubuntu 7 years ago? Mark: Ubuntu is designed to fulfill a dream of change; a belief that the potential of free software was to have a profound impact on the economics of software as well as its technology. It s obvious that the technology world is enormously influenced by Linux, GNU and the free software ecosystem, but the economics of software are still essentially unchanged. Before Ubuntu, we have a two-tier world of Linux: there s the community world (Debian, Fedora, Arch, Gentoo) where you support yourself, and the restricted, commercial world of RHEL and SLES/SLED. While the community distributions are wonderful in many regards, they don t and can t meet the needs of the whole of society; one can t find them pre-installed, one can t get certified and build a career around them, one can t expect a school to deploy at scale a platform which is not blessed by a wide range of institutions. And the community distributions cannot create the institutions that would fix that. Ubuntu brings those two worlds together, into one whole, with a commercial-grade release (inheriting the goodness of Debian) that is freely available but also backed by an institution. The key to that dream is economics, and as always, a change in economics; it was clear to me that the flow of money around personal software would change from licensing ( buying Windows ) to services ( paying for your Ubuntu ONE storage ). If that change was coming, then there might be room for a truly free, free software distribution, with an institution that could make all the commitments needed to match the commercial Linux world. And that would be the achievement of a lifetime. So I decided to dedicate a chunk of my lifetime to the attempt, and found a number of wonderful people who shared that vision to help with the attempt. It made sense to me to include Debian in that vision; I knew it well as both a user and insider, and believed that it would always be the most rigorous of the community distributions. I share Debian s values and those values are compatible with those we set for Ubuntu.

Debian would always be the most rigorous of the community distributions.

Debian on its own, as an institution, could not be a partner for industry or enterprise. The bits are brilliant, but the design of an institution for independence implies making it difficult to be decisive counterparty, or contractual provider. It would be essentially impossible to achieve the goals of pre-installation, certification and support for third-party hardware and software inside an institution that is designed for neutrality, impartiality and independence. However, two complementary institutions could cover both sides of this coin. So Ubuntu is the second half of a complete Debian-Ubuntu ecosystem. Debian s strengths complement Ubuntu s, Ubuntu can achieve things that Debian cannot (not because its members are not capable, but because the institution has chosen other priorities) and conversely, Debian delivers things which Ubuntu cannot, not because its members are not capable, but because it chooses other priorities as an institution. Many people are starting to understand this: Ubuntu is Debian s arrow, Debian is Ubuntu s bow. Neither instrument is particularly useful on its own, except in a museum of anthropology

Ubuntu is Debian s arrow, Debian is Ubuntu s bow.

So the worst and most frustrating attitude comes from those who think Debian and Ubuntu compete. If you care about Debian, and want it to compete on every level with Ubuntu, you are going to be rather miserable; you will want Debian to lose some of its best qualities and change some of its most important practices. However, if you see the Ubuntu-Debian ecosystem as a coherent whole, you will celebrate the strengths and accomplishments of both, and more importantly, work to make Debian a better Debian and Ubuntu a better Ubuntu, as opposed to wishing Ubuntu was more like Debian and vice versa. Raphael: The Ubuntu-Debian relationship was rather hectic at the start, it took several years to mature . If you had to start over, would you do some things differently? Mark: Yes, there are lessons learned, but none of them are fundamental. Some of the tension was based on human factors that cannot really be altered: some of the harshest DD critics of Canonical and Ubuntu are folk who applied for but were not selected for positions at Canonical. I can t change that, and wouldn t change that, and would understand the consequences are, emotionally, what they are. Nevertheless, it would have been good to be wiser about the way people would react to some approaches. We famously went to DebConf 5 in Porto Allegre and hacked in a room at the conference. It had an open door, and many people popped a head in, but I think the not-a-cabal collection of people in there was intimidating and the story became one of exclusion. If we d wanted to be exclusive, we would have gone somewhere else! So I would have worked harder to make that clear at the time if I d known how many times that story would be used to paint Canonical in a bad light. As for engagement with Debian, I think the situation is one of highs and lows. As a high, it is generally possible to collaborate with any given maintainer in Debian on a problem in which there is mutual interest. There are exceptions, but those exceptions are as problematic within Debian as between Debian and outsiders. As a low, it is impossible to collaborate with Debian as an institution, because of the design of the institution.

It is generally possible to collaborate with any given maintainer [ ] [but] it is impossible to collaborate with Debian as an institution.

In order to collaborate, two parties must make and keep commitments. So while one Debian developer and one Ubuntu developer can make personal commitments to each other, Debian cannot make commitments to Ubuntu, because there is no person or body that can make such commitments on behalf of the institution, on any sort of agile basis. A GR is not agile . I don t say this as a critique of Debian; remember, I think Debian has made some very important choices, one of those is the complete independence of its developers, which means they are under no obligation to follow a decision made by anyone else. It s also important to understand the difference between collaboration and teamwork. When two people have exactly the same goal and produce the same output, that s just teamwork. When two people have different goals and produce different product, but still find ways to improve one anothers product, that s collaboration. So in order to have great collaboration between Ubuntu and Debian, we need to start with mutual recognition of the value and importance of the differences in our approach. When someone criticises Ubuntu because it exists, or because it does not do things the same way as Debian, or because it does not structure every process with the primary goal of improving Debian, it s sad. The differences between us are valuable: Ubuntu can take Debian places Debian cannot go, and Debian s debianness brings a whole raft of goodness for Ubuntu. Raphael: What s the biggest problem of Debian? Mark: Internal tension about the vision and goals of Debian make it difficult to create a harmonious environment, which is compounded by an unwillingness to censure destructive behaviour. Does Debian measure its success by the number of installs? The number of maintainers? The number of flamewars? The number of packages? The number of messages to mailing lists? The quality of Debian Policy? The quality of packages? The freshness of packages? The length and quality of maintenance of releases? The frequency or infrequency of releases? The breadth of derivatives? Many of these metrics are in direct tension with one another; as a consequence, the fact that different DD s prioritise all of these (and other goals) differently makes for interesting debate. The sort of debate that goes on and on because there is no way to choose between the goals when everyone has different ones. You know the sort of debate I mean Raphael: Do you think that the Debian community improved in the last 7 years? If yes, do you think that the coopetition with Ubuntu partly explains it? Mark: Yes, I think some of the areas that concern me have improved. Much of this is to do with time giving people the opportunity to consider a thought from different perspectives, perhaps with the benefit of maturity. Time also allows ideas to flow and and of course introduces new people into the mix. There are plenty of DD s now who became DD s after Ubuntu existed, so it s not as if this new supernova has suddenly gone off in their galactic neighbourhood. And many of them became DD s because of Ubuntu. So at least from the perspective of the Ubuntu-Debian relationship, things are much healthier. We could do much better. Now that we are on track for four consecutive Ubuntu LTS releases, on a two-year cadence, it s clear we could collaborate beautifully if we shared a freeze date. Canonical offered to help with Squeeze on that basis, but institutional commitment phobia reared its head and scotched it. And with the proposal to put Debian s first planned freeze exactly in the middle of Ubuntu s LTS cycle, our alignment in interests will be at a minimum, not a maximum. Pure <facepalm />. Raphael: What would you suggest to people (like me) who do not feel like joining Canonical and would like to be paid to work on improving Debian? Mark: We share the problem; I would like to be paid to work on improving Ubuntu, but that s also a long term dream Raphael: What about using the earnings of the dormant Ubuntu Foundation to fund some Debian projects? Mark: The Foundation is there in the event of Canonical s failure to ensure that commitments, like LTS maintenance, are met. It will hopefully be dormant for good Raphael: The crowdfunding campaign for the Debian Administrator s Handbook is still going on and I briefly envisioned the possibility to create the Ubuntu Administrator s Handbook. What do you think of this project? Mark: Crowdfunding is a great match for free software and open content, so I hope this works out very well for you. I also think you d find a bigger market for an Ubuntu book, not because Ubuntu is any more important than Debian but because it is likely to appeal to people who are more inclined to buy or download a book than to dive into the source. Again, this is about understanding the difference in audiences, not judging the projects or the products. Raphael: Is there someone in Debian that you admire for their contributions? Mark: Zack is the best DPL since 1995; it s an impossible job which he handles with grace and distinction. I hope praise from me doesn t tarnish his reputation in the project!

---

Thank you to Mark for the time spent answering my questions. I hope you enjoyed reading his answers as I did.

Subscribe to my newsletter to get my monthly summary of the Debian/Ubuntu news and to not miss further interviews. You can also follow along on Identi.ca, Google+, Twitter and Facebook .

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It seems that in theory cruises can make for quite economical vacations. The cheapest prices tend to be around $100 per person per night for an inside cabin (IE no window) with two people (there is a significant extra fee for having a cabin with only one person). If you book a room in a half-decent hotel with a pool in some moderately desirable place then you will probably pay about $200 per night which might get you free breakfast but won t include lunch or dinner. Cruises include all the free food you can eat for at least 16 hours of the day with maybe an extra fee for getting food in the middle of the night. When a cruise ship stops at the port you can pay for an expensive shore trip arranged by the cruise company or have a cheap trip that involves walking on the beach or taking a taxi to somewhere local. Of course there are lots of extras that can make a cruise really expensive, but if you don t plan to eat at speciality restaurants or drink much alcohol then that shouldn t be a problem. I ve just booked a short luxury cruise, mostly as a trial of the cruise concept. The process of doing so was difficult enough that even if I hadn t previously needed a holiday then I d probably need one now. It would be interesting to compare the amount of time that a reasonable person would be likely to spend choosing a holiday and purchasing it for the different types of holiday, I expect that cruising would be a long way behind everything that involves flying to a foreign city and staying in a hotel. The Issues of Booking When booking a regular holiday you choose where to visit, then choose the time of year, the accommodation, and travel. While the order can vary it s generally a sequential process without too many variables at any stage. With a cruise one of the first decisions is to choose the cruise line, different lines cater to various market segments it s clear what Disney cruises aim for but often not so clear for others. Apart from Disney the other cruise lines don t seem to make clear statements about who they are and aren t targeting. Then there are a variety of ships run by each cruise line which in many cases offer different features, do you want 1 pool or 4? Do you want ice skating? The cruise lines that I have investigated don t offer clear comparisons of their ships. As a cruise ship is essentially a hotel, a collection of restaurants, and some other entertainment you can t just arbitrarily choose one the way you might choose a random hotel with a suitable price and rating. Now while you can choose a hotel and generally get a room when you want a cruise booking has to be made when the ship is in a convenient port. So your holiday needs to be scheduled around the availability of the ship. CruiseCritic.com is an excellent source of information on cruises and has a very active and useful advice forum [1]. The forum appears to be dominated by retirees, presumably because retirees have time to just wait for a ship they like to visit their local port while people who have to schedule holidays around work projects etc. When booking a hotel I have found that Wotif.com is really good for comparing hotels and finding a reasonably cheap one and they also have periodic mail-outs about special deals. I have made a couple of short vacations based on Wotif offering me unusually good prices on a hotel in a place that I was mildly interested in visiting. There are also special deals on cruises, but it s a lot more difficult to take them. Firstly as cruises aren t as interchangeable as hotels it s not as appealing to take an offer of a cruise you didn t previously consider because it s going cheap. The second factor is that according to cruise reviews there is more variation among cabins than there is among hotel rooms. The design of the ship that is needed to cram everything in the available space means that some cabins apparently have noise pollution from various activities on the ship while others are considered to have problems for people prone to sea-sickness. Discounts probably only apply after people who pay non-discount rates have had a chance to book what might be considered the better cabins. Of course it could be a good thing to have most of the ship booked out, CruiseCritic.com has some reviews of individual cabins and presumably there are people who compare hundreds of cabins to discover what is ideal for them. The Problem with Princess I have booked a Princess cruise. I chose it because it was going cheap, but the first two travel agents that advertised it were unable to take my order because Princess only allows US based agencies (which means the discount agents on the net) to sell to US customers I don t think that the people who run the Princess cruise company know what the Internet is about. So I booked the cruise through the Princess web site, they took my money, told me that a good chunk of that money would never be returned if I cancelled, and then sent me to the web page for providing all the information that they need which is a lot. The big problem was when their web site absolutely demanded a passport number and said that I would not be allowed to board without one even though their FAQ (and common sense) indicated that a cruise which doesn t involve any international travel has no need of a passport. Taking someone s money and then telling them that they can t attend due to not having a valid passport is one way of making a future passenger very unhappy. I called the support people (which was Carnival) and had to listen to some really strange hold music it was difficult to determine if the music was produced by someone with unusual tastes in electronic music vastly different from my own preference or whether the computer which manages the phone calls was producing noise instead of music. Eventually I got through to an operator who was very helpful and stored my drivers license number which was adequate. While on the topic of their web site, when booking a cruise with Princess they list which types of cabin (interior, balcony, etc) are available and list the price for the cheapest category of cabin in each price. However if the cheapest category is all sold out then it will still list that cheapest price and thus be advertising a price that can t be booked. This is misleading and annoying. Further Hassle But the difficulty doesn t end here. On a cruise you have to book in advance for which dinner seating you desire which is usually only early or late but some ships offer anytime . Then if you happen to be travelling with people who are in a separate cabin and paying separately (which one would expect to be fairly common) there is no obvious way of synchronising dinner preferences the ship people might assign people to different tables. I admit that I haven t fully explored the post-booking part of the Princess web site, maybe I can arrange a shared table but for the moment my pain threshold for the cruise booking process has been exceeded. Other Cruising Stuff Insight Cruises (formerly Geek Cruises) offers a variety of educational cruises including science, astronomy, chess, art, history, and some other things [2]. From a casual inspection of their web site it seems that the cruise prices are around $300 per night for a 2 person cabin and the registration fees for the conferences are between $1200 and $1500. Most readers of my blog will consider this to be unreasonably expensive as registration for a Linux conference tends to be a lot less than $1000. But when compared to typical for-profit conferences $1500 isn t anywhere near the high end of the range. Also while someone who is choosing a cruise holiday can easily get a cruise that costs less than $200 per day for a 2 person cabin, for commercial conferences it s not uncommon to spend more than $300 per night for two people on accommodation and food. So the only noteworthy part about the cost is that accommodation will be quite expensive if you aren t sharing a room. If you want to run a conference on a cruise there are companies which specialise in such things, Landry and Kling is one company that specialises in planning corporate events [3]. They do seem to aim for the high end of the market, including chartering a small cruise ship or half a large cruise ship that means ~1000 passengers. While there are some conferences with more than 1000 delegates it seems that most conferences top out at about 500 delegates. However I know that some conferences have limited the number of delegates to the maximum capacity of the biggest lecture hall available as some cruise ships have a theater with more than 1000 seats it seems that similar conferences could potentially arrange a half ship charter. A half ship charter apparently allows exclusive access to one of the theaters (at least when it s not needed for evening entertainment) and exclusive seating at the main dining room. It s a standard feature that cruise ships have all the equipment you might need to run a conference. Autism on the Seas is a brand used by the Alumni Cruise company for their holiday packages for special needs children [4]. They sell cruise tickets at the regular list price and the commission that they receive when acting as a travel agency is enough to hire staff to look after the kids while presumably still running at a profit. It seems to me that a similar model could be used for a computer conference, make a profit on cruise ticket sales and then have no extra costs for the conference for people sharing a room that would be cheaper than most Linux conferences I ve attended. For smaller conferences and un-conferences there is no minimum reservation size. One down-side for a computer conference is the cost of Internet access, according to Wikipedia a personal installation of satellite net access costs $5 per megabyte and ship pricing for their Internet access is up around $30-$100 per hour per person! But in the old days when attending a conference meant a week of no net access we survived somehow. It also seems to me that if a company had a small development team it could be productive to put everyone on a cruise ship with a server for testing and version control. They could do 9 hour days on board and still have lots of time for relaxation as it s only a few minutes walk to the pool. Of course this wouldn t work if some members of the team wanted to stay home due to slow and expensive net access.

• [1] http://www.cruisecritic.com/
• [2] http://insightcruises.com/
• [3] http://landrykling.com/
• [4] http://alumnicruises.org/Autism/Autism_Home.htm

Recently my installation of Qt SDK I use for development of applications for Nokia N950 (N9) got broken. It happened by update some postinst script failed what caused almost no part of Harmattan SDK to be installed. I hoped this to be temporary error which will get fixed by later updates, but it turned out to persist even for 1.1.4 which has been released week ago. Yesterday I finally got time to look into it and after some debugging I found out that it was trying to install x86_64 version, which was not downloaded because I was using 32bit installer. I quickly realized this was caused by using 64-bit kernel, while running 32-bit userspace, for which the installer somehow was not prepared. Fortunately there is easy workaround for that:

linux32 ./Qt_SDK_Lin32_online_v1_1_4_en.run

What will run the binary in 32-bit personality and make kernel pretend it is compiled for 32-bit.

Filed under: English Meego 2 comments Flattr this!

We've had sporadic Altus Metrum customer reports about RF susceptibility issues with their TeleMetrum installations. In almost every case, these problems have been completely resolved by either making sure the system battery has sufficient charge before launch, or through the application of standard engineering techniques such as twisting wire pairs to reduce differential coupling. However, even when every technique we could think of had been applied, once in a while someone still had issues. Around the time of LDRS this year, the incidence of such reports seemed to increase. One customer, in particular, had an installation in which he virtually always saw continuous resets of the board once his 54mm airframe was put on a launch rail, and several customers reported seeing board resets during ejection charge firing. Keith and I saw a board reset during main charge firing happen in person at NCR's Oktoberfest, and with a couple days available to work together after that launch, we decided it was time to figure out what was really going on. Here's what we've learned. In bench testing, it quickly became clear that the problem was the 3.3 volt power supply rail getting pulled down far enough to reset the CPU. This most frequently happened during ejection charge firing, when the input of the LDO regulator is pulled down by the near-short presented by the e-match when a pyro FET is turned on. To keep the 3.3 volt rail voltage up during firing, we include a 100uF bulk capacitor on the regulator's output. In all of our prior bench testing, we never saw the 3.3 volt rail droop significantly. Clearly something had changed... or maybe several things had changed? The first thing I wondered about was whether the new Kalman filtering code, which requires more compute cycles from the processor, might be consuming enough more power to pull the rail down faster during charge firing. After poking around at it, though, we have no data to suggest the new code makes a measurable difference in power consumption. The next thing we pondered was that at least some of the e-matches we and others are using in the hobby now come from the fireworks industry, where it is apparently considered a feature for the match to retain continuity after firing. This means the input of the LDO gets held down for longer than with the e-matches we used to use and Quest Q2G2 igniters that open when fired. But that still didn't make sense as the root cause, as we chose the FET firing time such that even with a dead short across the igniter terminals, the 3.3 volt rail wouldn't be pulled down far enough to cause trouble during firing. One of the big changes between v1.0 and v1.1 on TeleMetrum was that the newer boards incorporate a better reset circuit. This helps ensure the GPS chip always comes up running at power on, which was a problem at temperature extremes with older boards. However, a side-effect of this change is that a v1.1 board will reset any time the 3.3 volt rail drops below 3.15 volts, whereas older boards didn't trip until a much lower voltage. So the recent increase in reports might just be related to more v1.1 boards being placed in service? While experimenting on the bench, we observed that injecting RF energy into the input of the LDO regulator had the effect of pulling down the output voltage, presumably because the internal reference source accumulates charge and is fooled into thinking the output is too high. Since our designs all have the power switch contacts ahead of the LDO, the wires going out to the switch and back are effectively an antenna... as are, to a lesser extent, the wires going to the e-matches. There is some variability from part to part in just how badly the LDO reacts. But by attaching a tuned length of wire as an antenna to the LDO input and playing around, we were finally able to reproduce the problem reliably on a test board at my bench! On further analysis, we realized that the output of the USB battery charger chip and the input of the LDO both expect a 1uF bypass cap to ground. At some point, those looked redundant and we eliminated one of the two. Unfortunately, we weren't internalizing the fact that the switch leads were between the two caps, and the one we left was on the output of the charger and not at the input of the LDO. Placing a suitable bypass cap right at the input of the LDO turns out to have a truly dramatic effect on RF immunity! Once we realized that RF getting into the LDO input was the problem, Keith pointed out that we used to see "noise" in the accelerometer data on earlier boards that was caused by the 3.3 volt rail moving slightly during radio transmit, which we fixed with a hardware change on v1.1. We are now convinced that this was at least partly related to RF coupling to the LDO input, not just the change in power consumption on the LDO output. We didn't realize what was going on in earlier testing because we often didn't have ematches wired up, so RF coupling was minimal. But going back to flights logged with v1.0 boards that included deployment, and studying the magnitude of the "steps" in acceleration data observed when the transmitter was on, Keith was able to compute the amount the 3.3 volt rail must have sagged if the real acceleration wasn't changing... which in some cases was as much as 180mV! We think this proves that RFI could cause the LDO to drop its output voltage below the reset controller set point on v1.1 boards. Based on these observations, I'm making two hardware changes for the next version of TeleMetrum (version 1.2), and Keith is also making a software change. We have tested all of these changes on real boards both on the bench and in test flights, and the net effect is a major improvement in the RF immunity of TeleMetrum. The first hardware change is moving to a slightly lower trip voltage on the reset controller. Instead of 3.15, the new part trips at 3.00 volts nominal. This gives us more "headroom" to tolerate 3.3 volt rail droop during charge firing, and will allow the board to operate longer on a given battery charge. This change is not relevant for v1.0 and prior. The second hardware change is adding an appropriate bypass capacitor right at the LDO input. This requires a PCB update, but it's possible for me to update existing production boards by adding an 0402 cap right across the appropriate pins on the regulator chip. The software change prevents our altimeters from turning on the radio transmitter while an ejection charge is firing. Since the RF transmitter draws substantial additional power, this should help keep the 3.3 volt rail from drooping. This may not really matter, but it feels like the right thing to do. This change will be part of our next stable firmware release. We think most TeleMetrum customers need not worry about these updates. But if you have seen odd resets on the rail or during ejection charge firing in flight with a TeleMetrum v1.1, feel free to contact me about updating your existing board to include these improvements.

Back in the dark ages of the web, before the introduction of CSS 3, browsers could only display fonts available on the client system. Thanks to the introduction of @font-face and its now widespread support, this is over. Now, Web designers have access to a large selection of fonts and most users will be able to appreciate them. Typekit provides a subscription-based library of hosted, high-quality fonts to use on websites. I expose here my own, mostly uneducated¹ on the typographic side, look on this service.

Fonts embedding 101 There are several ways to embed fonts for the Web. Let s have a look at the most common ones.

Self-hosting and @font-face A first possibility is to host fonts yourself and provide a CSS file with the appropriate @font-face declarations. There are five important things to know:

1. There is no common format. You will need to host different versions of the same font to support most browsers.
2. Of course, Internet Explorer comes with its own quirks that you need to work around.
3. Most browsers enforce a same origin policy. You need to serve your fonts from the same domain as the requesting page. You can circumvent such a limitation by enabling cross-origin resource sharing: add an Access-Control-Allow-Origin header when serving fonts.
4. Fonts are unlikely to change. To leverage caching, configure an explicit expiration date far in the future. Something like 30 days.
5. There is no MIME types registered for fonts. Don t bother setting one, even if Google Chrome likes to complain about them in the console.

One great resource is Font Squirrel which provides kits with fonts and the appropriate CSS declarations. You choose your font family (or upload one of your own), the formats that you want to use (check them all) and you will get a ZIP archive with all fonts and a CSS file. You may want to tweak it a bit to enable automatic use of the bold variant when needed and to use a local copy if available. For example, if you choose Crimson, an oldstyle typeface, you may want to declare the bold version with font-weight: bold and add local names:

@font-face  
    font-family: 'Crimson';
    src: url('Crimson-Bold-webfont.eot');
    src: local('Crimson Bold'), local('Crimson Text Bold'),
         url('Crimson-Bold-webfont.eot?#iefix') format('embedded-opentype'),
         url('Crimson-Bold-webfont.woff') format('woff'),
         url('Crimson-Bold-webfont.ttf') format('truetype'),
         url('Crimson-Bold-webfont.svg#CrimsonBold') format('svg');
    font-weight: bold;
    font-style: normal;
 

Google Web Fonts For open-source fonts, you can also use Google Web Fonts instead of hosting the files yourself. Build a collection of fonts and choose the variants that you want to use for each of them. You will then be provided with a code snippet to paste in the <head> element of your page. For example, for Crimson:

<link href='http://fonts.googleapis.com/css?family=Crimson+Text:400,700,400italic'
      rel='stylesheet' type='text/css'>

Why choose this solution over self-hosting?

1. You don t use your own bandwith to serve fonts. This may be important if you pay for it.
2. Google uses its own CDN to serve fonts. If you don t use a CDN yourself, this can be a major performance improvement.
3. Caching is more efficient since many sites will use the same font.
4. It s easier to do it right.

Unless you are concerned about Google tracking your users², I think this is a better solution than self-hosting. Quick delivery of fonts is pretty important since content rendering can be delayed by them.

Paid services If you would like to use commercial fonts, like Adobe Minion Pro or Paratype Futura PT, a convenient option is to rent them. Typekit is service providing such an option. Pricing depends on volume and the number of fonts you want to have access to. There is a free plan and the first paid plan is US$24.99 per year. Other similar services exist. Feel free to compare. Once registered, the workflow is similar to Google Web Fonts. You choose your fonts, assemble them in a kit and publish it. Instead of directly providing a CSS file, Typekit provides some Javascript which will in turn download a CSS file containing all fonts in the appropriate format for the browser (on most browsers, fonts are inlined).

<script type="text/javascript"
        src="//use.typekit.com/tyt0atd.js"></script>
<script type="text/javascript">
  try Typekit.load(); catch(e) 
</script>

Typekit: the good parts So, why choose Typekit? First, there is the very large choice of fonts. The first paid plan comes with more than 500 fonts from about 80 foundries. There are about a hundred serif fonts and a couple hundred sans serif ones. Typekit provides a convenient interface to browse fonts. You can either search fonts by name or by characteristics. In the last case, you can filter on properties like the classification (serif, sans serif, decorative, etc.), weight, width, contrast, x-height, recommended use or language support. Once a font is selected and added to your kit, you can easily choose what variants you want. The kit total size is displayed. If you happen to meet any problem or have some questions, Typekit support is very responsive. I got clear and crisp answers in less than a few hours in the week-end.

and the bad ones Unfortunately, Typekit has also some shortcomings. One of the most commonly cited is that Javascript is mandatory. No Javascript, no fonts. If you want to display the appropriate fonts for users without Javascript, you should just not use Typekit.

Not free, nor free While Typekit offers some open-source fonts, most of them are not. Moreover, only a few of them are available in the free plan. While I would prefer to use open-source fonts, I don t consider this a strong requirement: if you are dissatisfied for some reason, switching back to open-source fonts (or another service) is fast and easy. I like serif fonts a lot and they get less attention from the FLOSS world: it is difficult to find one whose readability on screen is excellent. Droid Serif is a nice font but is a bit too black for me. Maybe Cardo would be a good match. You may disagree and in this case, Google Web Fonts or self-hosting seem the perfect match.

Difficulty to choose and test fonts While browsing fonts is easy and smooth, choosing and testing them is another matter. For example, Typekit is missing some interface to compare font rendering for whole paragraphs at a given size. It also misses a way to check how two fonts render together, one for headings and one for paragraphs. Here, Google Web Fonts is more versatile. Things become really difficult when you want to test your selected fonts for real. Except if you have invested into one of the expensive plans, you can only include a limited number of fonts in your kit. Each time you want to try another set of fonts, you need to modify your kit and wait for it to be distributed across Typekit network. You may have to wait five or ten minutes between each change! Another inconvenient thing is that once you publish your site, any change to the kit will affect the published version. Therefore, you need to use a second kit for development and play back and forth with those two kits. What would be convenient here is a special kit with all fonts from the library with restricted access to some IP to avoid abuse. This is something done by Fontdeck, a competitor.

Poor subset support Because you want to keep the font size small (about 30 kB for each variant), Typekit usually proposes two subsets: the default one contains only latin characters and the complete one with all glyphs. If some glyph is absent from the default subset, you need to use the complete one which is roughly two to four times the size of the default one. This is a bit huge for only one character. What would be nice is to have subsets for each language. In my case, I would take a French subset because I need the glyph which appears in French in words like c ur (heart or core) or il (eye). I don t want to select the complete subset just for this character. When a glyph is absent, the next font in the CSS stack is used. For example, if the selected font is FF Tisa Web Pro and the next font in the stack is Droid Serif, here is how the word c ur may be rendered. On the first line, FF Tisa Web Pro contains the appropriate glyph. On the second line, the glyph is absent and taken from Droid Serif. Since x-height and contrast are a bit different, the replaced glyph seems out of tone. At small sizes, the difference accounts for more than 10%. I have also added a third line where the ligature is built from o and e and the following style is applied to e :

.lf-ligature  
    margin-left: -0.172em;
    zoom: 1; /* Here to trigger hasLayout on IE7 */
 

As you can see, the result seems good. I have a piece of Javascript turning a ligature into the appropriate markup. It can be extended to handle more ligatures and could be adapted to handle other composed characters (like the ones in Anton n Dvo k ).

Defective caching Because a document can only be rendered after the fonts have been loaded³, it is pretty important to deliver fonts as fast as possible. Typekit uses Edgecast as a CDN and DynECT for DNS hosting. Two files are downloaded. Both of them are hosted on use.typekit.com. The first one is a script that will act as a loader. Based on the characteristics of your browser, it will choose how to download the requested fonts for best rendering. The second file is generally a big CSS file containing the fonts. Here are the headers returned for the first file:

HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: max-age=300
Content-Encoding: gzip
Content-Type: text/javascript
Date: Tue, 08 Nov 2011 18:34:16 GMT
ETag: "388467610+gzip"
Expires: Tue, 08 Nov 2011 18:39:16 GMT
Last-Modified: Sat, 05 Nov 2011 09:31:57 GMT
Server: ECS (cdg/D624)
Vary: Accept-Encoding
X-Cache: HIT
Content-Length: 7440

First, notice that the content is served compressed. Good point. The next headers to look at are Cache-Control, Date, ETag and Expires: the server requests the content to be cached for 5 minutes. When the browser notices that its copy is out-of-date, it will issue a new request including a If-None-Match: 388467610+gzip header. Unless the kit has been modified, the server will answer with 304 Not Modified and no content. The copy of the browser will be valid for another 5 minutes. This means that after 5 minutes, at least 3 round-trips are needed to check if our fonts are up-to-date. Worse, sometimes, Typekit servers may be just slow. They can wait one second before answering, just to send a 304. Since the first file is a script embedded in <head>, the whole page is blocked until you get the answer. Here is an illustrative example with Chromium 14 where a page using Typekit is loaded while all static assets are in the navigator cache and things have gone wrong (which is pretty rare): Since fonts are needed, the rendering has been paused for 3.5 seconds until Typekit was fully loaded. If we look more closely, we may also notice we got a status 200 from the server instead of 304. Here is an excerpt of the browser request:

GET /tyt0atd.js HTTP/1.1
Host: use.typekit.com
Connection: keep-alive
Accept-Encoding: gzip,deflate,sdch
If-None-Match: "2200251225+gzip"
If-Modified-Since: Thu, 10 Nov 2011 11:38:11 GMT

And here is an excerpt of the answer headers:

HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: max-age=300
Content-Type: text/javascript
Date: Fri, 11 Nov 2011 17:10:03 GMT
ETag: "2200251225"
Expires: Fri, 11 Nov 2011 17:15:03 GMT
Last-Modified: Thu, 10 Nov 2011 11:38:11 GMT
Server: EOS (lax001/54E5)
Content-Length: 25755

What happened? For some unknown reason, the server denied the access to the compressed version of the resource: there is no Content-Encoding: gzip while the browser did send Accept-Encoding: gzip. The tag provided by the browser (2200251225+gzip) came obviously from the compressed resource and therefore does not match. RFC 2616 requests If-Modified-Since header to be ignored if the tag does not match. Consequently, the server answers with 200 OK and resend the whole file. The same problem happened with the CSS file. Let me stress again how important the problem is: we had to download again the two files but we also downloaded the non-compressed version. Now, let s suppose that we did not run into this problem and the server answered with 304 Not Modified. The result is still not satisfactory: we would have waited 1.3 seconds to get both answers from the server. Keep in mind that most of the time, Typekit is pretty fast. Here is how I think this should have been done: each time you modify your font kit, you get a new URL to use (containing the version of the font kit for example). This resource and the associated fonts (whose URL is also versioned) are requested to be cached for several days. As a sidenote, this also enables to modify a kit for your development environment without modifying the kit for your production site. I suspect that Typekit did not go this way to track kit usage more accurately and enforce the appropriate pricing. Having multiple versions of the same kit would also allow us to use more fonts that we are paying for. UPDATED: Typekit support knows the problem and is working on it:

You ve identified a small bug in our CDN provider that we re working with them to fix. Hopefully I can give an explanation of what s happening. The CDN edge servers have a cache of recently served kits on them. Any request that is served from that cache will be correctly Gzipped and handle ETags. Unfortunately, if the content isn t already in cache and needs to be fetched from the master origin server then the request won t be gzipped correctly which has the side effect of breaking ETags. [ ] We are working to on getting this bug fixed, but any change to a globally distributed CDN will take some time. We re also working on having our content cached longer than 5 minutes whilst still allowing people to quickly update their site.

Conclusion I have mixed feelings about Typekit. While the difficulty to test fonts and the lack of language-related subsets are annoying, I have been able to work around them. However, the caching problem is more annoying. I am still considering going back to Google Web Fonts just because of this.

---

1. While I have a high interest in typography, have my own copy of The Elements of Typographic Style by Robert Bringhurst and have throughly read The Elements of Typographic Style Applied to the Web , I am still fairly novice on this matter.
2. Google serves fonts from a cookie-less domain. Technically, they could still do some kind of tracking but I believe they don t.
3. In fact, browsers have different strategies on how to render before fonts availability. Paul Irish wrote a comprehensive article on FOUT. One common strategy is to render a blank space until downloaded fonts are available. If this takes too much time, fallback fonts may be used.

A few years ago, I ran into my friend Jay in the MIT Infinite Corridor. He was looking for volunteers to have their pictures taken and then added to the library of freely licensed and remixable media that would ship with every version of Scratch -- the graphical programming language built by Mitch Resnick's Lifelong Kindergarten group that is designed to let kids create animations and interactive games. Jay suggested I make some emotive faces and I posed for three images that made the final cut: But although I've spent quite a bit of time studying the Scratch community in the last few years as it is grown to include millions of participants and projects, I forgot about about Jay's photo shoot. A couple months ago, Acetarium resident Andres Lombana Bermudez pointed out that there was a mako tag on the Scratch website and that a whole bunch of users had been publishing projects using the pictures of me which, apparently, shipped in Scratch under my name. For example, in this project in which I dance in front of a enormous "MAKO" banner: That said, given the rather emotive nature of the pictures, I seem to usually end up being blown up shot, shrunk, set on fire by dragons, or meeting other similarly unfortunate ends. There's quite many more entertaining examples under the tag and many more elsewhere on the Scratch website although they are a little trickier to track down. Jonathan Zittrain likes to say that the best technologies are generative in the sense that they encourage their users to make things with them that the designer never forsaw or anticipated. I feel generative.

Today I was removing KDE from my laptop, when I realized that kde-window-manager would not go away (even when it was automatically installed) since it provides x-window-manager, which is needed by gdm. I manually removed it, but that got me thinking that maybe I had other packages that were in this situation. So I picked aptitude and tried to build some search-fu. Here is the resulting query:

aptitude search '?for x:

 ?x:installed

 ?x:automatic

 ?x:provides(?virtual ?reverse-depends(?installed))

 ?not(?x:reverse-depends(?installed(?depends(?=x))))'

Now, lets go over the query. The first part ?for x: allows us to refer to the package currently being matched. See the documentation for details. We'll see later why we need this. Basically we are saying: give me all packages x that match the following pattern. The second and third parts are trivial: we only want automatically installed packages.
The fourth part, ?x:provides(?virtual ?reverse-depends(?installed)) was easy: find all packages that provide a virtual package that is depended upon by some other installed package.
The fifth and final part, ?not(?x:reverse-depends(?installed(?depends(?=x)))) is why we needed the bound variable x. We want to filter out (hence the ?not) the packages that have some reverse dependency that depends directly on the package x. That way, in my case, metacity won't show up since gnome-core directly depends on it and is installed.

Unfortunately, this query doesn't grok alternative dependencies. For example, if gnome-core depended on metacity x-window-manager then this query wouldn't show metacity, since it is depended upon by a package. If someone can make this query understand that so that it only eliminates packages directly depended upon with no alternatives dependencies, please let me know!Tags: aptitude, cleaning, tip, tips

First event of my trip was somewhat a gimmick: Give a 30 minutes talk on FreedomBox to an audience of 1 person, in the transit area of Heathrow airport, London. A guy from India now living in London helped preparing my visit to India, an was eager to participate - so much that he was willing to drive out to the airport to meet me. The meeting failed, unfortunately: My flight got delayed, and my one-man "audience" got caught in other duties. Fun to try nevertheless. Also looking back, that crazy attempt to squeeze in a meeting during a 1 hour stop-over was an indicator of the general pace of the India trip This text is part of my Asia 2011 scriblings.

I've been unable to solve this problem for a few weeks now, so i'll try posting it to my blog maybe someone out there knows the answer. Would very much appreciate a clue on this one. I've got a VM on a citrix xenserver 5.0.0 machine that won't start. it was running fine until it was rebooted on a Fri afternoon, a few weeks ago. Starting it from the (windows-only) xencenter GUI results in:

   "This VM cannot be started, as its network interfaces could not be
   connected. One of the NICs is in use elsewhere."

Starting it from the command line results in:

# xe vm-start uuid=88915b63-d794-e021-4f78-b03f46e352b0
Cannot plug VIF
VIF: 5dfd3886-8b48-20e5-4231-30284d7b185d

anyone seen this before? know how to fix? I've tried deleting and re-creating the network interface for the VM. I've also tried booting the VM without any network interface at all. I've tried "xe vif-unplug force uuid=5dfd3886-8b48-20e5-4231-30284d7b185d" (doesn't work, expects the VM to be running, not halted). In fact, I've lost track of all the things i've tried doing that haven't worked. I haven't rebooted the xen server and *really* don't want to have to do that. I'd rather create a new VM and copy the OS (debian, fortunately so relatively easy to do) than reboot the server (NOTE: Tried that, didn't work). Since the initial problem, I now have a total of three VMs that won't restart (with the same error message), and I can't even create a new VM. So it looks like a problem with the host rather than the guest. I think i'm going to have to migrate all the VMs off this machine to another box, then rebuild this server. maybe with a newer Xen (on debian, rather than proprietary citrix junk), or maybe as a KVM box. The (absence of) this kind of crap is one of the main reasons why i prefer KVM to Xen .and if i have to rebuild the server anyway, I may as well rebuild it as a KVM server Xen VMs won t start: Cannot plug VIF is a post from: Errata

You're on a small island in the middle of a vast ocean. There's nothing but dirt, stone and grass on the your island, which is part of a tiny archipelago. One of the nearby islands features a dark cave, with what looks like a coal seam near the entrance. You can glimps two small trees on another island nearby. All around your little clutch of islands is what appears to be vast, unending ocean in all directions. It's midday and you need to make yourself safe for the night. You can use the wood from the trees to craft a pickaxe. With this, you can fetch some coal from the seam. With the coal, you can create some torches, to see in the dark. You might have enough wood left over to make a door, if you're lucky. Or perhaps you should save it to craft a boat, or a sword. Groans from something unknown emanate worryingly closely from the darkness of the cave. You're lucky: one of your two trees has dropped a sapling. You eagerly plant it. In a few days time, you might be able to harvest some more wood. You've been granted a temporary reprieve, but the law of diminishing returns means at some point, and soon, you'll run out of wood. Swimming is time-consuming. By the time you have assembled a meagre supply of wood and coal, it's almost sunset. You nervously dig a burrow in the mud of your original island, light it with a torch and block the entrance back up. Night passes slowly as you listen to things crawling around in the darkness outside. I first learned about Minecraft from this blog post by Mike Watson last year. Mike did a great job of demonstrating the narrative power of the game and his post left a lasting impression on me. Every now and then I dip in to Minecraft to see what's new since the last time I played it. In the last few months version 1.8 was released and so I started a new map to check it out. I ended up with a corker of a randomly-generated map. Inspired by Mike's post, I thought I'd write a bit about it. In a follow-up post I will provide the map itself.

Oh, boy. Where do I start I postulate that there exists something called the "UI Singularity". Those who spend too much time considering the optimal way to interact with computing devices eventually pass through this singularity and can no longer effectively communicate with those of us on the other side. At least that's one way to explain what seems to be happening to free-software desktop environments. From the outside, it would appear this happened to KDE with KDE 4, and now, unfortunately, it has happened to GNOME, with GNOME 3. I've had GNOME 3.0 running on my Debian laptop for a few months, which I have used casually. At work, we installed Fedora 15 (GNOME 3.0) on our 69-seat Linux lab over the summer, which I have used on occasion to achieve specific things. I haven't dared upgrade my main work machine yet. So, it could be argued that I haven't spent enough time immersed in the GNOME 3 experience to really judge it fairly. On the face of it, I wish 3 was an iterative development from 2, and didn't throw so many babies out with the bathwater. My casual use of it so far has not endeared it to me at all. In the interests of being fair, rather than deliver my opinion of GNOME 3 as it currently stands, I've decided to try and use it in anger for a while to truly see whether I can "get it". Now that we're past the start of term, I am attempting to use a lab-configured Fedora 15 machine as my main work environment. I'll run with this for a while, and then try a Fedora 16 instance (I need to consider whether we should move to F16 for the second semester anyway) to see what improvements GNOME 3.2 brings.

This is a follow-up on a previous post: I used a bit of a rainy Sunday to read some docs and write some Python, and I now have a script that converts events from a Guitar Hero World Tour drums controller to MIDI. A brief explanation of how it works: in its standard configuration, the drums controller has five pads and a pedal, and it uses a Wiimote to communicate the events (what pad was hit with what force, or what button was pressed/released, or the position of the mini-stick) to the Wii itself. This communication happens over Bluetooth and not over a dedicated cable or protocol, so it is possible to remove the Wii and use a standard computer with Bluetooth (built-in or via a dongle) instead, and the computer will receive messages. There's some decoding to do, but fortunately people have reverse-engineered the frames, and come up with the libcwiid library and its Python binding, which hides the complexity of the decoding and just delivers structured data to the programs that use it. Then we analyze this data and extract the relevant info from it (with some juggling of bits): "the X pad was hit with force Y". From there, it's a simple matter of mapping the pads to a MIDI note and the force to a MIDI velocity, and of sending the appropriate MIDI message to the target, for instance with the libportmidi library. What you do with the MIDI output is your call: I use it to add more pads to my electronic drum kit, but it could equally be used to drive a software synthetizer, or an external sound module. Or a light-show machine. Or fireworks. Or a model railway. Or whatever. Here's the current version of the wiigh2midi.py script (for updated versions, see the Bazaar repository).

#! /usr/bin/python
import cwiid, time, asyncore, pypm
class Wiimidi:
    wiimote = None
    midiout = None
    lastaction = time.time()
    wii2color =   27: 'kick',
                  25: 'red',
                  17: 'yellow',
                  15: 'blue',
                  14: 'orange',
                  18: 'green'  
    color2midi =   'kick': 36, # Bass drum
                   'red': 38, # Snare drum
                   'blue': 48, # High tom
                   'green': 43, # Low tom
                   'yellow': 42, # Closed hi-hat
                   'orange': 52, # Crash cymbal
                    
    def connect_wiimote(self):
        print "Press 1+2 on the Wiimote..."
        try:
            self.wiimote = cwiid.Wiimote()
        except:
            self.wiimote = None
            return None
        print "Connected."
        self.lastaction = time.time()
        self.wiimote.rumble=1
        time.sleep(.2)
        self.wiimote.rumble=0
        return self.wiimote
    def disconnect_wiimote(self):
        if self.wiimote is not None:
            print "Closing connection to the Wiimote."
            self.wiimote.close()
            self.wiimote = None
        return
    def connect_midi(self):
        for i in range(pypm.CountDevices()):
            interf,name,inp,outp,opened = pypm.GetDeviceInfo(i)
            if outp == 1:
                if name == 'UM-1G MIDI 1':
                    self.midiout = pypm.Output(i, 0)
                    return
        for i in range(pypm.CountDevices()):
            interf,name,inp,outp,opened = pypm.GetDeviceInfo(i)
            if outp == 1:
                print i, name," ",
                print
        dev = int(raw_input("Type output number: "))
        self.midiout = pypm.Output(dev, 0)
    def wiimote_callback(self, messages, timestamp):
        self.lastaction = time.time()
        m = messages[0][1]
        # rx = m['r_stick'][0]
        ry = m['r_stick'][1]
        l = m['l']
        # r = m['r']
        which = ( (l << 1) & 16) + (ry >> 1)
        softness = l & 7
        if softness == 7 or which == 0:
            return
        # print "rx=%d\t ry=%d\t l=%d\t r=%d\t rest=%d" % (rx,ry,l,r,rest)
        # print "which = %d, softness = %d" % (which, softness)
        strength = 7-softness
        color = self.wii2color[which]
        midi_vel = 16*strength
        midi_note = self.color2midi[color]
        self.midiout.WriteShort(0x9a,midi_note,midi_vel)
        self.midiout.WriteShort(0x9a,midi_note,0)
        # print "%s %d -> %d %d" % (color, strength, midi_note, midi_vel)
    def main(self):
        self.connect_midi()
        while True:
            if self.wiimote is None:
                self.connect_wiimote()
                if self.wiimote:
                    # Tell Wiimote to display rock sign
                    self.wiimote.led = cwiid.LED1_ON   cwiid.LED4_ON
                    # We only care for the extension data
                    self.wiimote.rpt_mode = cwiid.RPT_EXT
                    self.wiimote.enable(cwiid.FLAG_MESG_IFC   cwiid.FLAG_REPEAT_BTN)
                    self.wiimote.mesg_callback = self.wiimote_callback
                    self.lastaction = time.time()
                else:
                    print "Retrying... "
                    print
            asyncore.loop(timeout=0, count=1)
            if self.lastaction < time.time() - 3600:
                print "An hour passed since last action..."
                self.disconnect_wiimote()
            time.sleep(0.05)
        print "Exited safely."
# Instantiate and run
inst = Wiimidi()
inst.main()

There are a few obvious improvements to be made: first, handling guitar controllers in addition to drums. Second, handling the buttons could provide extra "pads", to trigger sound effects for instance (thunder, lasers, voices ), or to initiate program changes, or to change the mappings of the pads. Maybe storing the mutable parts (default MIDI adapter, pad-to-note mapping) in a configuration file. Maybe add a user interface to ease the configuration. Patches welcome, otherwise maybe I'll do that myself on another rainy Sunday. Notes and references (in other words, the giants on whose shoulders this program stands):

• As mentioned, this script uses the pyPortMidi binding, available in Debian Wheezy as python-pypm (and easily backported to Squeeze).
• It also uses the Python bindings to CWiid, available in Debian as python-cwiid.
• I based the pad-to-MIDI mapping on the relevant part of the General MIDI specification.
• The bit-mangling operations used to map cwiid messages to plain data were worked out by comparing the tables from the Wiibrew wiki on the classic controller and the drums controller.
• The skeleton of the script was initially based on MythPyWii, although not much of it still remains.

More cowbell!

It's about time that Rapha l is interviewed in the "People behind Debian" series he initiated on his blog. Indeed, when he interviews people, Rapha l asks about other people they could suggest for next interviews. So, during mine, I suggested him to be a next "victim". As he couldn't interview himself, I volunteered for this. As you'll see below, Rapha l (who's a friend of mine as I'm a friend of his) likes to speak and that shows in the length of his answers :-) but you always know more about Debian when reading his blog posts, books, mails, etc. I personnally think that he is among the best promoters of the project for years and it was a pleasure for me to conduct this interview. My questions are in bold, the rest is by Rapha l. Who are you? Hi, Rapha l Hertzog, I'm a 32 years old French Debian developer who is married and who has a 2-year old son. I'm running my own company (Freexian) since 2005, I started it 3 years after the end of my computer science studies. I'm also a very proud author of the Cahier de l'Admin Debian, a French book about Debian. You often wrote about your attempts to make your living partly, if not completely, out of your Debian work. Can you describe the way you're trying to do this? My first try has been with Freexian. I always advertised this company as being specialized in Debian GNU/Linux. While Freexian is successful enough to provide me a decent income, I'm not really satisfied with the result because very few of my contracts are about improving Debian. I use Debian daily for the benefit of my customers, writing new customer specific (embedded) software, deploying a service on Debian servers, etc. But except for the occasional bugfix, all this work does not improve Debian (the only exception has been the dpkg multiarch implementation work sponsored by Linaro). The positive side is that I don't need to fill my entire schedule to earn enough money to live. So I'm regularly taking some days off work to be able to contribute to Debian. This is a freedom that I enjoy... My French book has also been a bestseller and depending on the years the royalties represented between 1 and 2 months of supplementary time that I can spend on Debian (that is between 2000 and 4000 EUR of income). Now since last year, I decided to actively work towards my goal of making a living out of my Debian work. I want to build on what has been most successful for me up to now, that is my book. My strategy has been to build an audience around my blog: with a direct contact with my readers I have the opportunity to sell e-books, and without any intermediary taking the biggest part of the price, I don't need a very large audience to be successful. I have also been experiencing micro-donations with Flattr, people who are enjoying my articles on my blog can use it to give a few cents for each article they find useful. With a large enough userbase, this could fund free documentation and would avoid the need for commercial e-books but we're not there currently and I don't know if it will ever reach the critical mass. Last but not least, I'm soliciting donations for my Debian work on the sidebar of my blog, and I have the chance to a have a few (regular) donators. You're a proud father since last year. How do you manage your commitment to the project with your family life? There are few things that I put above Debian in my life, but my family certainly is. I try to handle most of my Debian duties during work hours so that I can spend time with my family on evenings and during week-ends but in truth I never really disconnect from Debian. It happens quite often that I say to my wife I'll come in a few minutes, let me finish this and then I end up responding to a Debian mail, or an IRC query and take 30 minutes instead of the 5 expected ones. I try hard to avoid this but it's difficult. Luckily for me, my wife is very supportive of my Debian involvement and knows me well... By the way my wife is using Debian on her computer, and my son has already played with DoudouLinux (a Debian derivative!). Have you already been accused of self-promotion in your writings? If that would ever happen, what would you answer to that? Yes, more than once. I am proud of what I do for Debian, I enjoy sharing the result of my work. Because of this, some people believe that I'm selfish and egocentric. And this has somewhat increased since I have been soliciting donations: for me it's important to be transparent towards donators so that they see what I really do for Debian. But some people have the feeling that I'm getting undeserved attention and that I bring everything towards my own person. On the other side, as an author, I'm a public figure who is definitely seeking some attention... I don't have any miraculous answer, we are a large and diverse community, it's next to impossible to please everybody. I listen to all the concerns that people bring forward, I take them into account as much as possible, in particular when I believe they are reasonable/well justified, or when they come from people that I highly respect. But sometimes I have to plainly ignore them too... in particular when they are trying to impose their own political view on a topic that's not directly related to the only value that we all share: the social contract. Contributing to Debian is a challenge, we all have to make efforts to put aside our differences and to concentrate on the work that brings us closer to the best free software operating system ever built. You recently launched a campaign to free out the soon-to-be-published "Debian Administrator Handbook", an English version of your well-known book about Debian in French. Can you tell us more about this project? My French book has been very successful at helping people to get started with Debian, and like I already explained, it was also effective to fund a part of my Debian work. So I wanted to make it available world-wide by publishing an English translation of it. I tried to find an English-speaking editor willing to take on the challenge but I found none interested. Not put off by a setback, Roland (my co-author) and I decided to negotiate with our French editor Eyrolles to recuperate the necessary rights to translate the book into English. Handling everything ourselves represents a lot of work, but it also means that we have the freedom required to decide of the license of the resulting book. We would love to see it under a license compatible with the Debian Free Software Guidelines. But at the same time we firmly believe that we deserve a reasonable monetary compensation for the work on the book, so we conditioned its liberation to a predefined amount of money (25 K ) in what we call the "liberation fund". And since we wanted to be sure that we would have the required means to complete the translation, we used a crowfunding platform to seek support of people interested by the book. With such a platform you're only debited if the minimal requested amount is reached. Anyone can participate, pre-order the book and/or put some money in the liberation fund. As of today, we already reached the minimal funding goal (15 K ) so the book translation will happen. But the liberation target has not yet been reached so we don't know yet if the book will be free from the start... you can follow the progress right on the fundraising page or on the website dedicated to the book. PS: If you want to contribute to this project and also make a donation to Debian at the same time, you should check out this page. You're one of the main developers of dpkg, a critical tool for Debian systems. Can you tell us more about the current development challenges it is facing? What will be the new dpkg features for wheezy? The current challenges are not really technical. dpkg is a relatively mature piece of software and it will continue to work for the foreseeable future without needing much maintenance work. The real challenge is trying to setup a healthy developement community around it so that we can keep tackling new interesting problems (there are many listed in the roadmap and in the 225 wishlist bugs). There is a real problem of leadership and communication in the current team. We used to be three, and we're only two nowadays. Guillem is the legitimate leader since he's involved in dpkg's developement since early 2006 while I joined only in late 2007. But in the last 4 years, we did not manage to recruit anyone else on the team. Some persons tried to contribute significant new features (like Sean Finney with a rework of the way we handle configuration files) but they gave up frustrated after a while because we did not manage to review their work (and discuss the design) in any reasonable timeframe. Another famous case is Ian Jackson with his trigger work. His work got merged, but so late that in the mean time he blew up while trying to hijack the maintenance of dpkg. For a long time I was concentrating my work on the Perl part of dpkg (aka dpkg-dev mainly), so I did not feel qualified to review and merge work related to the C part and I was just a worried observator of this situation. I tried to improve it by setting up some basic review infrastructure, it should have brought some lisibility to the status of each change left to be reviewed... but it has not been used and it changed nothing. Over the years, I became much more interested in the C part. My first big contribution in C has been the rewrite of update-alternatives (from Perl to C). I made other small changes in between, but at the start of this year I had this great opportunity to work on the multiarch implementation (FYI, multiarch is the possibility to mix packages from several architectures on a single system). This really forced me to jump into the C codebase and learn a lot about how dpkg is implemented. Thanks to this I have been able to tackle other small projects (like the improved triggers). This would be all great if my multiarch work was already merged, but it's not. It's a large work, I do not mind waiting a bit in particular since Guillem is a highly skilled C programmer. His sharp analysis of new designs are invaluable, when he reviews code he always finds something to improve. I learnt a lot just by reviewing the code he wrote over the years. That said I have been waiting since April without almost no updates from him. With the release team asking us to hurry up, the situation is getting somewhat strained as I really want to see multiarch in Wheezy and I do not really want to short-circuit Guillem. Hum, I may have drifted a bit from your original question... what great new features can people expect? Well multiarch is supposed to be the big new feature, apart from that there aren't many things that matter to the end users. But there are already quite a few changes that are of interest to package maintainers (like hardened build flags, source package improvements, improved triggers, ). What's the biggest problem of Debian? Manicheism and a tendency to quickly polarize the discussions. In reality, there are very few situations where everything is all good or all bad. Ever since I have read The 7 Habits of Highly Effective People I try hard to put into practice the habits of interdependence . Instead of having only my point of view in mind, I try to understand the motivations from the other party ( Seek First to Understand, Then to be Understood ) in order to be able to put forward solutions acceptable to both parties ( Think Win-Win ). I highly recommend this book to anyone. And I invite everybody to at least try to follow those simple advices. Is there someone in Debian you admire for their contributions? There are many and I can't give an exhaustive list... here are some that I would like to highlight (in no particular order):

• Niels Thykier for the work he puts into Lintian, and his recent work on a britney test-suite (the software that creates testing out of unstable);
• Joachim Breitner for his britney reimplementation using a SAT solver;
• Adam D. Barrat for his work on britney2;
• All the release team members who take care of an endless stream of transitions;
• Christoph Berg for his continuous work over the years on various QA infrastructure (DDPO, Mole, );
• Enrico Zini for the way he helped reform the New Member process without any big disruption;
• Russ Allbery for his Debian Policy work and for being a model in terms of how we should interact on Debian mailing lists;
• Stefano Zacchiroli for being the most active leader that I have ever seen, and for the way he tries to steer important discussions to a constructive conclusion.
• etc.

Most of those people are working on improving Debian's infrastructure so that we can all be more effective and do an even better work. This kind of work is not always very visible but it's crucial to Debian's future. Thank you to Rapha l for the time spent answering my questions. I hope you enjoyed reading his answers as I did. And, anyway, it was fun to just play the game "the other way".