And before you know it, another week has passed… I arrived back home yesterday, sooner that I had expected. The flight, landing and taxiing went very quickly and smoothly; this is probably to compensate for the enormously slow and dramatic check-in and boarding. I had a great time meeting all the Debian people, getting to know each developer’s backgrounds, talking, discussing, eating, etc. In my opinion, the people at Debconf and especially the organisation team cannot be thanked enough for making this possible, so here we go: thank you very much everyone, for making Debconf 7 possible and fun. :-) See you in Argentina, I hope! My own photos containing some general impressions will follow shortly. Though, I left most of the Debconf photographing to people with real cameras and some of these photo have already been published on the Debconf 7 gallery.

There is some effort here at Debconf to improve Debian’s game stuff. I want to contribute to that by announcing my first upload of the game “Feeding Frenzy!” to Debian Sid. The game is about dwarfs (or sheep) that have to collect food to survive which becomes increasingly scarce during the game. Besides collecting food, the dwarfs can also can choose to throw the food at competing dwarfs to temporarily disable them. Four years ago, a group consisting of some of my friends and myself created this game as an assignment for a project in our bachelor computer science. A few weeks ago, we undusted the game, Bram fixed some compiler warnings and I fixed up the package. It is ready for Debian now and has a pretty good gameplay, though it can probably still be improved graphic- and level-wise. I uploaded it two days ago. So, if our FTP-masters are no longer busy with Debconf, I hope they can get the game through the NEW queue soon.

The Debian/Ruby Extras team has come to an agreement about a meeting time and date, yay! We’re going to meet today, Tuesday June 19, 2007 and discuss current packaging issues, plans for the future, and the Ruby policy. I’m delighted that half of the members of the team are here and are able to get together. Invitation If anyone is interested in joining the team or observing what we do, please meet us at 18:00 in front of the cafeteria. Oh, and could somebody at least bring a computer, because my PowerBook is not as portable anymore as it used to be. Update: I forgot to mention that most team members usually hide out on IRC in the #debian-ruby channel on OFTC.

It is time for a DebCamp update, since I’ve been here three days now. I have mainly been working on picking up the slack regarding Debian/Ruby Extras. This meant: getting rid of a CDBS rule that substitutes the entire team in the Uploaders field, cleaning up some package, uploading some packages with new upstream, solving and filing bugs. During all this, the “picture” of the environment outside is actually only missing yellow/brown trees shedding their leaves. Ruby D-Bus 0.2.0 In between the Debian/Ruby Extras work I have been able to finish the documentation of our Ruby D-Bus protocol implementation. It is due for release this weekend and I think we’ll make it.

I have just arrived in Edinburgh. The flight was just fine. The weather is a bit foggy and cold (compared to NL), but it is exactly how I remember it. I was transported to MACS at the Heriot-Watt university. It’s weird to sit on my old working spot again. :-)

Yesterday, I have completed my master project with a presentation of my work and a defence of my thesis. I got awarded a 9 (out of 10) for my entire project. It is a result that I am very happy with and am very proud of. This result will allow me to get my Master of Science degree with honours on June 19, after the exam committee has checked everything. Note that the diploma will be handed out not on June 19, but on August 28, because I am on my holiday and at Debconf in Edinburgh the next two weeks. Thanks everyone for attending my presentation, joining the “celebration lunch” afterwards, and all the encouraging words and kudos. :-)

I just realised that I forgot to post about take 2, so I’ll combine it with this post about take 3. The past five months I’ve been busy with examining the effect of restriction on CCS with parallelism. We decided to do this in two steps. First (take 2) we considered interleaving of actions, and then (take 3) we added communication. The case with only interleaving of actions went smoothly; it worked out as a nice extension of the case without parallelism. However, when we looked at the case with interleaving and communication, it started to become troubling. I ran into all kind of complications and the risk of failure I described in a previous post seemed to come true. However, I think we managed quite well to catch a large part of the problems and describe them, and also offer possible solutions. In the end, I’m quite happy of the result. So, today I can present the final version of my Master’s Thesis: “Finite Equational Bases for CCS with Restriction”. Yay! I have just submitted it for reproduction. The final presentation of my project will take place June 5, 2007 at 10:00 in the main building of the university, HG 6.29. If you’re interested and are able to attend, consider yourself invited. I want to thank Bas Luttik for his large amount of feedback, clear explanations and guidance, without him the project wouldn’t have worked out as well as it did now. Almost finished, 6 days remaining…

Since Spring is well underway, I wanted to post a sort of schedule summary of my activities in the following three months. First of all, I have registered and booked the flight for Debconf 7, yay! I can stay with friends of mine that I know from the time I worked in Edinburgh. I want to thank Krzysztof for this offer, it saves a lot of money and it will be nice to catch up. Besides Debconf, there are also several nice parties and events this spring, and of course the completion of my master project.

• 2007-04-19: Finish my Master Project paper
• 2007-05-16: Finish my Master thesis
• 2007-05-17: A State of Trance 300 celebration outdoor
• 2007-06-01: Master Project presentation (date not definite)
• 2007-06-12— 2007-06-26: Attend Debconf7, holiday in Edinburgh
• 2007-07-19: Official graduation date (ceremony postponed till 2007-08-28)
• 2007-07-07: Intuition Summer event!

And after that,... who knows? It probably should involve some work in the summer and maybe an ad-hoc holiday. I’m looking at several options: maybe do a PhD, maybe working for Google or maybe something completely different. More about that later.

In response to Joey’s IPv6 autoconfiguration troubles: Over the years I’ve gotten IPv6 autoconfiguration working just as you described: load the module and bring the interface down and back up. Though, I suspect you may have been running Debian’s linux-image-2.6.18-3- arch kernel which seemed to drop/neglect/whatever (I haven’t checked the specifics) IPv6 multicast (link-local) traffic over which the autoconfiguration is done. When 2.6.18-4 arrived in Sid, all worked fine for me after a reboot too.

Hobix There were some issues concerning Hobix and the new Ruby (1.8.6) that entered Sid recently. I’ve solved the problem, as you can see, and uploaded a Subversion snapshot package to experimental. Update: It seems that hobix 0.5~svn20070319-1 accidently was uploaded without share data. This was spotted and fixed by Arnaud, thanks! A new version (0.5~svn20070319-2) is on its way to experimental! Ruby D-Bus A few weeks ago I wrote to Arnaud Cornet about the fact that it is quite amazing that there is no up-to-date implementation of D-Bus for Ruby at all after such a long time. This resulted a few days ago in our Ruby D-Bus project. Some stuff is working already, quite low-level still, but really nice. I’m looking forward to designing the high-level API. I found out that other people had the same thoughts as us and also started to work on an implementations on their own without telling anyone. So, it seems there are three implementions now (as far as I know) that all have specific features working. I hope we can merge everything into one project. We’ll see what happens… OpenID I have taken some interest into OpenID, having to register some accounts on arbitrary forums. I ran into the fact that Rails recently got OpenID support and that support for phpBB is coming up, which is nice. Finally it could be over with all the logins and all the password. At the moment I haven’t found a statisfactory identity provider yet, so I started working on my own service. Ruby OpenID has an example server implementation which I am working on to become FLOIDS: the Free Luon OpenID Service. Koditoj Recently, I inventoried all the programs I authored or co-authored in the past 8 years. There is some stuff in there that maybe deserves a second life or at least some description. So, in a series of posts that I’ll call ‘Koditoj’ (free translatable from Esperanto to ‘things that have been coded’) I want to go over all these programs and libraries and give them some attention. More to come soon…

Last Tuesday I finished my paper about Space Efficient Algorithms and Histograms that will comprise most of the grade of my last remaining Master course, Advanced Algorithms. While I’ve been mostly enjoying writing this paper, I am glad it is finished for several reasons, one of them being able to do other things than just working on it and another is that it allows me to focus fully on my Master Project which is starting to progress nicely. (More about this later.) FOSDEM 2007 Due to the amount of time I needed to work on the paper, the need to save money (I really would like to go to Debconf7) and that the scheduled talks didn’t seem to interest me that much, I decided to break with tradition and not to go to FOSDEM this year. Just before FOSDEM, however, it seemed that lots of the people I would have liked to meet did go. While that was a pity, I hope to meet them in three months at Debconf7.

With 2006 almost finished, I can look back at a succesful year for the Debian/Ruby Extras team. The infrastructure was set up and we gained 12 new team members and a lot of packages. With Etch frozen, I can now almost certainly say what Etch will bring Ruby-wise:

• 35 new libraries and applications.
• A meta-package libruby-extras to extend the Ruby Standard Library with some more useful libs.
• Consistent packaging of the 44 team-packaged apps and libs.
• RubyGem support (courtesy of Daigo Moriwaki)

I am proud of what we have accomplished, good work everyone! Not team related is the change that the whole Ruby stdlib is now bundled in libruby(1.8) and is no longer split up! So you all can remove those Debian-specific messages about having to “do extras things when using Debian”. ;) Future plans for Lenny Future plans for Lenny include updating and extending the Ruby Policy. Focus points will be package versioning, improving documentation. Also we intend to package even more Ruby libraries and applications and ask current Ruby lib/app developers to join us. A third matter I’d like to address is Gem support.

Today I have effectively started with my Master Project! I have been been at it for a few days already in the past weeks though, but now I’m sitting on my own spot working on some proofs. So, what am I actually doing? Well that’s still hard to put in words yet and it also requires some process algebra and general math prior knowledge, but I’ll try. My graduation supervisor is Bas Luttik and in July he co-published a paper on defining a finite equational base (a set of equations from which all others can be derived) for a specific process algebra called CCS. This paper used a specific subset of CCS, namely without restriction (hiding) and relabelling. Restriction is an operator of the process algebra to block certain actions of happening, relabelling is an operator to replace actions by other actions. Take 1 of my project is to try to consider this algebra with restriction and finding a new equational base and proof that either it works or it can not be done. This is a risky assignment because it can lead to: we have tried but haven’t gotten either results. The short period to come will entail considering CCS with restriction but without concurrency to drastically reduce the cases to be considered. If we succeed, we’ll continue with CCS with restriction and concurrency. If we do not succeed it’s quite possible we’ll change my project assignment. More to come!

I read The @ Book by Patrik Sneyd from ascii64 last Wednesday. It tells the story of the @ (at-sign) and elaborates on all kinds of (sometimes seemingly un)related topics such as spam, software patents, Michelangelo, morse code, etc. using either symbolic images or short texts. This booklet with a really nice layout is a refreshing read during a break. @:)

After finishing Hypermedia and History of Computing in October I was ready to meet the requirements of the bachelor’s exam. I passed it on November 14 and received my Bachelor of Science in Computer Science last Monday. While before the BaMa (Bachelor Master) system was introduced this 3-year milestone might have meant nothing at all, so it feels kind of odd that I have finished a study now. I’ve updated my CV. I hope I can do this again soon, namely when I’ll finish my Master of Science…

During the past weeks I’ve been drawing up a list with things to be done for the Etch release concerning my work for the Debian/Ruby Extras team. I think it is quite complete now. I hope my fellow team members can help me accomplish these goals:

• Solve all remaining issues concerning the ruby-pkg-tools.
• Make sure that all team-maintained packages are:
  • bug-less, that is, no open priority minor or higher bug reports,
  • installable,
  • up-to-date with respect to the upstream version.
• Consider all work-in-progress packages and get them in Etch if they are worthy.
• Take over the packages put up for adaption by Damog.
• Create the libextras-ruby meta-package and get it into Etch.

I think the first two items are as good as taken care of. However, the last three points need some more attention the next few weeks.

This weekend I was finally able to finish (after 7 days of full-time labour) the assignment of my last pending bachelor course: Hypermedia Structures and Systems. The assignment of this purely on-line course consisted of the conversion of a linear document to a hypertext one. This meant splitting the document in dozens of nodes and then going through each of them (iteratively) and linking them together using several techniques while keeping useful guidelines in mind. While discussing this assignment with Bas we decided it would be nice to build the site using Webgen. Webgen is good at transforming nodes that just contain text (with a bit of Textile markup) to nice XHTML 1.1 valid pages. We also extended Webgen with a few plug-ins: one to create links to nodes without having to mention the paths but just using unique identifiers. That way we were sure the links were also always pointing to the right page. The other plug-in we wrote was to be able to do bibliography stuff a la LaTeX. I am quite satisfied with the result, which will be graded this week. ;)

There was no real known reason why our essay for the course History of Computing was overdue, but Bas and I finally managed to finish it yesterday. Almost two years we have been postponing writing it, slowly collecting and reading more material, but after a few weekends of hard work, it is done: John Vincent Atanasoff: The Inventor of the Digital Computer (copyrighted under CC SharedAlike 2.5) The essay tries to acknowledge Atanasoff’s accomplishments, the ABC, and ideas that we still find in our computers today (binary system, regenerative memory, separation of calculation and memory and calculation by electronics and logic). Without these ideas and the derivations that found its way into the ENIAC, the world would’ve been a different place for sure. I was surprised by the increased amount of work it requires to write a work covering a historical topic. For each sentence you write down, you either have to do a lot of research, you have to make sure it is objective or if it is not objective you have to find a source backing up what you are stating. This way, writing 1,5 pages on an average Saturday is a lot, comparing to writing a report about some practical assignment, which is fairly easy and straightforward. Even more so since our topic is surrounded by controversy.

I finally decided to move the Jabber server of luon.net to a different server. Our main luon.net server was being fairly loaded for weeks because of the business of the S2S component. The transition was a lot easier than I had expected and everyone got to keep his/her JID. Some tips/hints concerning the steps I took:

• First I moved all our services’ DNS names to a CNAME of jabber.luon.net, that is:

   msn 1800 IN CNAME jabber
   icq 1800 IN CNAME jabber
   s2s 1800 IN CNAME jabber
   c2s 1800 IN CNAME jabber
   ...

  Note that jabber.luon.net still has the same addresses as luon.net at this time.
• I also added SRV records for luon.net so XMPP servers and some of the clients can find us right away. (Since the server won’t be running on luon.net anymore, the @luon.net-JIDs still will let everything try to contact us there). The SRV records used:

   _jabber._tcp 1800 IN SRV 5 1 jabber.luon.net.
   _xmpp-client._tcp 1800 IN SRV 5 1 jabber.luon.net.
   _xmpp-server._tcp 1800 IN SRV 5 1 jabber.luon.net.

• With that done, I installed all components we use on the new machine, rsynced the configuration, restarted the server and services and tested the connection.
• Then, I modified the address of jabber.luon.net to point to the new host and let it propagate.
• Next, I sent a MOTD (luon.net/announce/motd) about our server move and notified the users that if their clients do not support SRV records, they will not be able to login anymore and they’ll have to change the server address in the client¹.
• Finally, I installed a second C2S component on luon.net that connects to the main XMPP router component on the other host for transition purpose. I’ll leave it on for two weeks.

It’s a pity that SRV records aren’t used more these days. But I guess the whole sub-domain and multiplex-by-CNAME stuff came earlier (why doesn’t your website start with ‘www.’?).

¹ I thank Google for introducing the gmail.com JIDs <-> talk.google.com server discrepancy so that now all clients can configure the server separately from the JID.

Next to upgrading my journal software I have also replaced the software powering my normal homepage. I used to use Hobix for that, but I have replaced it with Webgen. Don’t get me wrong, both are good pieces of software, but Hobix is just nicer for writing a journal and Webgen for generating webpages from simple formatted content. But in the end, both produce nice static HTML pages! :-) Note that my normal homepage is emptier than it used to be, but given the low threshold to add something I am sure more will come soon. I also updated my style a bit to synchronize the look of the pages produced by both frameworks, but it was quite trivial in the end.