Search Results: "Daniel Silverstone"

1 November 2015

Daniel Silverstone: A haiku about Haiku

I know I don't mention a season, and I'm a few hours late for hallowe'en, but here's a haiku about Haiku:
A death, once again,
The master sighs, and fixes,
It rises up, undead.

8 September 2015

Daniel Silverstone: Orchestration, a cry for help

Over the past few years, a plethora of orchestration frameworks have been exploding onto the scene. Many have been around for quite a while but not all have the same sort of community behind them. For example there's a very interesting option in Joey Hess' Propellor but that is hurt by needing to be able to build Propellor on all the hosts you manage. On the other hand, Ansible is able to operate without installing extra software on your target hosts, but instead it ends up very latency-bound which can cause problems when your managed hosts are "far away". I have considered CFEngine, Chef, Puppet and Salt in addition to the above mentioned options, but none of them feel quite right to me. I am looking for a way to manage a small number of hosts, at least one of which is not always online (my laptop) and all of which are essentially snowflakes whose sparkleybits I want some reasonable control over. I have a few basic requirements which I worry would be hard to meet -- I want to be able to make changes to my hosts by editing a file and committing/pushing it to a git server. I want to be able to manage a host entirely over SSH from one or more systems, ideally without having to install the orchestration software on the target host, but where if the software is present it will get used to accelerate matters. I don't want to have to install Ruby or PHP on any system in order to have orchestration, and some of the systems I wish to manage simply can't compile Haskell stuff sanely. I'm not desperately interested in learning yet more DSLs, but I appreciate that it will be necessary, but I really don't want to have to learn more than one DSL simply to run one frameworks. I don't want to have to learn strange and confusing combinations of file formats. For example, Ansible quite sensibly uses YAML for its structured data except for its host/group lists. It uses Jinja2 for its templating and looping, except for some things which it generates its own looping constructs inside its YAML. I also personally find Ansible's sportsball oriented terminology to be confusing, but that might just be me. So what I'm hoping is that someone will be able to point me at a project which combines all the wonderful features of the above, with a need to learn only one DSL and which doesn't require to be installed on the managed host but which can benefit from being so installed, is driven from git, and won't hurt my already overly burdened brain. Dear Lazyweb, pls. kthxbye.

24 July 2015

Vincent Sanders: NetSurf developers and the Order of the Phoenix

Once more the NetSurf developers gathered to battle the forces of darkness, or as they are more commonly known web specifications.

Michael Drake, Vincent Sanders, John-Mark Bell and Daniel Silverstone at the Codethink manchester officesThe fifth developer weekend was an opportunity for us to gather in a pleasant setting and work together in person. We were graciously hosted, once again, by Codethink in their Manchester offices.

Four developers managed to attend in person from around the UK: Michael Drake, John-Mark Bell, Daniel Silverstone and Vincent Sanders.

The main focus of the weekends activities was to address two areas that have become overwhelmingly important: JavaScript and Layout.

Although the browser obviously already has both these features they are somewhat incomplete and incapable of supporting the features of the modern web.
JavaScriptThe discussion started with JavaScript and its implementation. We had previously looked at the feasibility of changing our JavaScript engine from Spidermonkey to DukTape. We had decided this was a change we wanted to make when DukTape was mature enough to support the necessary features.

The main reasons for the change are that Spidermonkey is a poor fit to NetSurf as it is relatively large and does not provide a stable API guarantee. The lack of a stable API requires extensive engineering to update to new releases. Additionally support for compiling on minority platforms is very challenging meaning that most platforms are stuck using version 1.7 or 1.85 (current release is version 31 with 38 due).

We started the move to Duktape by creating a development branch, integrating the Duktape library and open coding a minimal implementation of the core classes as a proof of concept. This work was mostly undertaken by Daniel with input from myself and John-Mark. This resulted in a build that was substantially smaller than using Spidermonkey with all the existing functionality our tests cover.

The next phase of this work is to take the prototype implementation and turn it into something that can be reliably used and covers the entire JavaScript DOM interface. This is no small job as there are at least 200 classes and 1500 methods and properties to implement.
LayoutThe layout library design discussion was an extensive and very involved. The layout engine is a browsers most important component. It takes all the information processed by the CSS and DOM libraries, applies a vast number of involved rules and produces a list of operations that can be rendered.

This reimplementation of our rendering engine has been in planning for many years. The existing engine stems from the browsers earliest days more than a decade ago and has many shortcomings in architecture and implementation we hope to address.

The work has finally started on libnslayout with Michael taking the lead and defining the initial API and starting the laborious work of building the test harness, a feature the previous implementation lacked!
The second war beginsFor a war you need people and it is a little unfortunate that this was our lowest ever turnout for the event. This is true of the project overall with declining numbers of commits and interest outside our core group. If anyone is interested we are always happy to have new contributors and there are opportunities to contribute in many areas from image assets, through translations, to C programming.

We discussed some ways to encourage new developers and try and get committed developers especially for the minority platform frontends. The RISC OS frontend for example has needed a maintainer since the previous one stepped down. There was some initial response from its community, culminating in a total of two patches, when we announced the port was under threat of not being releasable in future. Unfortunately nothing further came from this and it appears our oldest frontend may soon become part of our history.

We also covered some issues from the bug tracker mostly to see if there were any patterns that we needed to address before the forthcoming 3.4 release.

There was discussion about recent improvements to the CI system which generate distribution packages from the development branch and how this could be extended to benefit more users. This also included authorisation to acquire storage and other miscellaneous items necessary to keep the project infrastructure running.

We managed over 20 hours of work in the two days and addressed our current major shortcomings. Now it just requires a great deal of programming to complete the projects started here.

1 July 2015

Daniel Silverstone: Be careful what you ask for

Date: Wed, 01 Jul 2015 06:13:16 -0000
From: 123-reg <>
Subject: Tell us what you think for your chance to win
X-Mailer: MIME::Lite 3.027 (F2.74; T1.28; A2.04; B3.13; Q3.13)
Tell us what you think of 123-reg!
.style1  color: #1996d8 
Well 123-reg mostly I think you don't know how to do email.

11 June 2015

Daniel Silverstone: In defence of curl sudo bash -

Long ago, in days of yore, we assumed that any software worth having would be packaged by the operating system we used. Debian with its enormous pile of software (over 20,000 sources last time I looked) looked to basically contain every piece of free software ever. However as more and more people have come to Linux-based and BSD-based systems, and the proliferation of *NIX-based systems has become even more diverse, it has become harder and harder to ensure that everyone has access to all of the software they might choose to use. Couple that with the rapid development of new projects, who clearly want to get users involved well before the next release cycle of a Linux-based distribution such as Debian, and you end up with this recommendation to bypass the operating system's packaging system and simply curl sudo bash -. We, the OS-development literati, have come out in droves to say "eww, nasty, don't do that please" and yet we have brought this upon ourselves. Our tendency to invent, and reinvent, at the very basic levels of distributions has resulted in so many operating systems and so many ways to package software (if not in underlying package format then in policy and process) that third party application authors simply cannot keep up. Couple that with the desire of the consumers to not have their chosen platform discounted, and if you provide Debian packages, you end up needing to provide for Fedora, RHEL, SuSE, SLES, CentOS, Mint, Gentoo, Arch, etc.etc; let alone supporting all the various BSDs. This leads to the simple expedience of curl sudo bash -. Nobody, not even those who are most vehemently against this mechanism of installing software, can claim that it is not quick, simple for users, easy to copy/paste out of a web-page, and leaves all the icky complexity of sorting things out up to a script which the computer can run, rather than the nascent user of the software in question. As a result, many varieties of software have ended up using this as a simple installation mechanism, from games to orchestration frameworks - everyone can acknowledge how easy it is to use. Now, some providers are wising up a little and ensuring that the url you are curling is at least an https:// one. Some even omit the sudo from the copy/paste space and have it in the script, allowing them to display some basic information and prompting the user that this will occur as root before going ahead and elevating. All of these myriad little tweaks to the fundamental idea improve matters but are ultimately just putting lipstick on a fairly sad looking pig. So, what can be done? Well we (again the OS-development literati) got ourselves into this horrendous mess, so it's up to us to get ourselves back out. We're all too entrenched in our chosen packaging methodologies, processes, and policies, to back out of those; yet we're clearly not properly servicing a non-trivial segment of our userbase. We need to do better. Not everyone who currently honours a curl sudo bash - is capable of understanding why it's such a bad idea to do so. Some education may reduce that number but it will never eliminate it. For a long time I advocated a switch to wget && review && sudo ./script approach instead, but the above comment, about people who don't understand why it might be a bad idea, really applies to show how few of those users would even be capable of starting to review a script they downloaded, let alone able to usefully judge for themselves if it is really safe to run. Instead we need something better, something collaborative, something capable of solving the accessibility issues which led to the curl sudo bash - revolt in the first place.
I don't pretend to know what that solution might be, and I don't pretend to think I might be the one to come up with it, but I can hilight a few things I think we'll need to solve to get there:
  1. Any solution to this problem must be as easy as curl sudo bash - or easier. This might mean a particular URI format which can have os-specific ways to handle standardised inputs, or it might mean a pervasive tool which does something like that.
  2. Any solution must do its best to securely acquire the content the user actually wanted. This means things like validating SSL certificates, presenting information to the user which a layman stands a chance of evaluating to decide if the content is likely to be what they wanted, and then acting smoothly and cleanly to get that content onto the user's system.
  3. Any solution should not introduce complex file formats or reliance on any particular implementation of a tool. Ideally it would be as easy to implement the solution on FreeBSD in shell, or on Ubuntu as whizzy 3D GUIs written in Haskell. (modulo the pain of working in shell of course)
  4. The solution must be arrived at in a multi-partisan way. For such a mechanism to be as usefully pervasive as curl sudo bash - as many platforms as possible need to get involved. This means not only Debian, Ubuntu, Fedora and SuSE; but also Arch, FreeBSD, NetBSD, CentOS etc. Maybe even the OpenSolaris/Illumos people need to get involved.
Given the above, no solution can be "just get all the apps developers to learn how to package software for all the OS distributions they want their app to run on" since that way madness lies. I'm sure there are other minor, and major, requirements on any useful solution but the simple fact of the matter is that until and unless we have something which at least meets the above, we will never be rid of curl sudo bash - :- just like we can never seem to be rid of that one odd person at the party, noone knows who invited them, and noone wants to tell them to leave because they do fill a needed role, but noone really seems to like. Until then, let's suck it up and while we might not like it, let's just let people keep on curl sudo bash -ing until someone gets hurt.
P.S. I hate curl sudo bash - for the record.

9 June 2015

Daniel Silverstone: Sometimes recruiters really miss the point...

I get quite a bit of recruitment spam, especially via my LinkedIn profile, but today's Twitter-madness (recruiter scraped my twitter and then contacted me) really took the biscuit. I include my response (stripped of identifying marks) for your amusement:
On Tue, Jun 09, 2015 at 10:30:35 +0000, Silly Recruiter wrote:
> I have come across your profile on various social media platforms today and
> after looking through them I feel you are a good fit for a permanent Java
> Developer Role I have available.
Given that you followed me on Twitter I'm assuming you found a tweet or two in
which I mention how much I hate Java?
> I can see you are currently working at Codethink and was wondering if you
> were considering a change of role?
I am not.
> The role on offer is working as a Java Developer for a company based in
> Manchester. You will be maintaining and enhancing the company's core websites
> whilst using the technologies Java, JavaScript, JSP, Struts, Hibernate XML
> and Grails.
This sounds like one of my worst nightmares.
> Are you interested in hearing more about the role? Please feel free to call
> or email me to discuss it further.
Thanks, but no.
> If not, do you know someone that is interested? We offer a  500 referral fee
> for any candidate that is successful.
I wouldn't inflict that kind of Lovecraftian nightmare of a software stack on
anyone I cared about, sorry.
I then decided to take a look back over my Twitter and see if I could find what might have tripped this. There's some discussion of Minecraft modding but nothing which would suggest JavaScript, JSP, Struts, Hibernate XML or Grails. Indeed my most recent tweet regarding Java could hardly be construed as positive towards it. Sigh.

9 May 2015

Daniel Silverstone: Kimchi Trial 1 - Part 1

I have spent today making my first ever batch of Kimchi. I have been documenting it in photos as I go, but thought I'd write up what I did so that if anyone else fancies having a go too, we can compare results. For a start, this recipe is nowhere near "traditional" because I don't have access to certain ingredients such as glutinous rice flour. I'm sure if I searched in many of the asian supermarkets around the city centre I could find it, but I'm lazy so I didn't even try. I am not writing this up as a traditional recipe because I'm kinda making it up as I go along, with hints from various sources including the great and wonderful Maangchi whose YouTube channel I follow. Observant readers or followers of Maangchi will recognise the recipe as being close to her Easy Kimchi recipe, however since I'm useless, it won't be exact. If this batch turns out okay then I'll write it up as a proper recipe for you to follow. I started off with three Chinese Leaf cabbages which seemed to be about 1.5kg or so once I'd stripped the less nice outer leaves, cored and chopped them. Chopped up cabbage I then soaked and drained the cabbage in cold water... Soaking cabbage ...before sprinkling a total of one third of a cup of salt over the cabbage and mixing it to distribute the salt. Salted Cabbage Then I returned to the cabbage every 30 minutes to re-mix it a total of three times. After the cabbage had been salted for perhaps 1h45m or so, I rinsed it out. Maangchi recommends washing the cabbage three times so that's what I did before setting it out to drain in a colander. Drained salted cabbage 1h45m later Maangchi then calls for the creation of a porridge made from sweet rice flour which it turns out is very glutinous. Since I lack the ability to get that flour easily I substituted cornflour which I hope will be okay and then continued as before. One cup of water, one third of a cup of cornflour was heated until it started to bubble and then one sixth of a cup of sugar was added. Stirred throughout, once it went translucent I turned the heat off and proceeded. Porridge thingy One half of a red onion, a good thumb (once peeled) of ginger, half a bulb of garlic and one third of a cup of fish sauce went into a mini-zizzer. I then diagonal-chopped about five spring onions, and one leek, before cutting a fair sized carrot into inch long pieces before halving and then thinly slicing it. Maangchi calls for julienned carrots but I am not that patient. Veggybits Into the cooled porridge I put two thirds of a cup of korean hot pepper flakes (I have the coarse, but a mix of coarse and fine would possibly be better), the zizzed onion/garlic/ginger/fish mix and the vegetables... All in the pan ...before mixing that thoroughly with a spatula. Mixed vegetables Next came the messy bit (I put latex gloves on, and thoroughly washed my gloved hands for this). Into my largest mixing bowl I put a handful of the drained cabbage into the bowl and a handful of the pepper mix. Thoroughly mixing this before adding another handful of cabbage and pepper mix I repeated until all the cabbage and hot pepper mixed vegetables are well combined. I really got your arms into it, squishing it around, separating the leek somewhat, etc. Bowl of kimchi As a final task, I scooped the kimchi into a clicklok type box, pressing it down firmly to try and remove all the air bubbles, before sealing it in for a jolly good fermenting effort. I will have to remove a little tonight for our dinner (beef strips marinated in onion, ginger and garlic, with kimchi on rice) but the rest will then sit to ferment for a bit. Expect a part-2 with the report from tonight's dinner and a part-3 with the results after fermentation. Box of kimchi
As an aside, I got my hot pepper flakes from Sous Chef who, it turns out, also stock glutinous rice flour -- I may have to get some more from them in the future. (#notsponsored)

Daniel Silverstone: Kimchi Trial 1 - Part 2

Last night we tried the small amount of 'fresh kimchi' from my epic kimchi making trial. I marinaded some beef strips in a blended paste of onion, garlic, ginger, and sesame oil for a few hours before frying that up, and serving on rice with stir-fried carrots, leek and spring onion. A little fresh kimchi on the side for flavour. Delicious dinner I think the Kimchi was a success. Dearest Rob said that it tasted of Kimchi. The flavours were not very well combined and quite clearly underdeveloped, and the pepper flakes were still a little hard. I expect this to resolve over the next few days as it begins to ferment. All in all, experiment going well, expect part 3 when I know how it tastes after fermentation begins.

Daniel Silverstone: Kimchi Trial 1 - Part 3 - Kimchiguk

Earlier this week I allowed some of my colleagues at work to try the Kimchi and one of them (James) liked it enough to ask for a tub of it just for himself. Being a lovely person I obliged. My darling Rob decided that what he really wanted was Kimchiguk or Kimchijijae. Being both wonderful and lacking in ingredients, I set to do achieving something. I read a few recipes, worked out that I lacked critical ingredients and so set about simulating Kimchiguk. I grabbed two and a bit cupfuls of kimchi from the box in the fridge, chopped it up more finely, popped it into a pot along with about a pound of cubed pork belly, two teaspoons of hot pepper flakes, two teaspoons of sugar, and two teaspoons of cornflour. I then topped that off with five cups of water, mixed it up, brought it to the boil and simmered it for 30 minutes. Then I cubed some tofu, popped that in and simmered it for another 10 minutes while some rice cooked. Served in a bowl over rice, my approximation of Kimchiguk turned out pretty well. (Note it fed both of us and there was a serving left over.) Kimchiguk - Kimchi soup With a do-over, I'd try harder to get pork shoulder (belly is quite fatty) and given the option I'd wait until I had hot pepper paste because the malty fermented sweetness of hot pepper paste is pretty much impossible to emulate otherwise.

13 February 2015

Neil Williams: OpenTAC mailing list

After the OpenTAC session at Linaro Connect, we do now have a mailing list to support any and all discussions related to OpenTAC. Thanks to Daniel Silverstone for the list. List archive: More information on OpenTAC:

17 November 2014

Vincent Sanders: NetSurf Developer workshop IV

Michael Drake, John-Mark Bell, Daniel Silverstone, Rob Kendrick and Vincent Sanders at the Codethink manchester office
Over the weekend the NetSurf developers met to make a concentrated effort on improving the browser. This time we were kindly hosted by Codethink in their Manchester office in a pleasant environment with plenty of refreshments.

Five developers managed to attend in person from around the UK: Michael Drake, John-Mark Bell, Daniel Silverstone, Rob Kendrick and Vincent Sanders. We also had Chris Young providing some bug fixes remotely.

We started the weekend by discussing all the thorny core issues that had been put on the agenda and ensuring the outcomes were properly noted. We also held the society AGM which was minuted by Daniel.

The emphasis of this weekend was very much on planning and doing the disruptive changes we had been putting off until we were all together.

John-Mark and myself managed to change the core build system as used by all the libraries to using standard triplets to identify systems and use the gnu autoconf style of naming for parameters (i.e. HOST, BUILD and CC being used correctly).

This was accompanied by improvements and configuration changes to the CI system to accommodate the new usage.

Several issues from the bug tracker were addressed and we put ourselves in a stronger position to address numerous other usability problems in the future.

We managed to pack a great deal into the 20 hours of work on Saturday and Sunday although because we were concentrating much more on planning and infrastructure rather than a release the metrics of commits and files changed were lower than at previous events.

6 January 2014

Vincent Sanders: NetSurf Developer Workshop Redux

The NetSurf Developers bringing you alternative LOLcat viewing software since 2002Once again the NetSurf developers congregated in Cambridge at the Collabora offices where we were made welcome in a nice environment for the event.

Five developers managed to attend from around the UK Rob Kendrick, Vincent Sanders, Daniel Silverstone, John-Mark Bell and Michael Drake. We also had Chris Young and Fran ois Revol providing some bug fixes remotely.

This was the first time we had all met since the previous event towards the end of 2012 and we took full advantage of this to discuss a pretty extensive agenda in addition to the practical programming tasks.

From Friday lunchtime through to Sunday evening we managed 30 hours of work consisting of over 70 commits to over 100 files.

The whiteboard of our notes

Our main focus was working towards a 3.1 release which is scheduled for early April. Along with the source the release will have binary builds for RISC OS, AmigaOS, Windows and Mac OS X (x86 and ppc). Although the NetSurf project will not be directly releasing binaries for the GTK and Framebuffer frontends we will be ensuring the Debian packages are updated which is our prefered method of distribution for those targets.

We analysed the 3.0 release and formulated an improved process for the future. The 3.1 release will be generated automatically by the CI system ensuring constant results and removing the problems we encountered previously.

A set of release blocking issues was derived which we used as a task list during the workshop.The majority of these were completed including:
DOM based forms
Web forms are a feature Netsurf has supported for a long time and their implementation has not kept up with the rest of the browser. This is a long standing problem area which has resulted in numerous strange bugs with form submission. With this change the form system has been reworked to correctly operate directly from the DOM resulting in the squashing of a large number of bugs and a much improved user experience.

DOM based image loading
Up to now image fetching was performed only during the rendering of a page. With this change when the image link is placed into the DOM during the page parse it is scheduled to be fetched, this should give an improved user experience as images should be available earlier in a pages render.

Removal of MNG support
NetSurf has supported MNG since the 1.0 release, indeed the MNG library used to provide the PNG support too though we have long ago transitioned to libPNG. Alas the web has moved on and MNG has been largely forgotten, the libMNG library that performs the image decoding is old and generally unsupported specifically lacking security updates.

The build issues with libMNG (lack of pkg-config, reliance on libcms1 etc.) were causing maintenance issues in code nobody was actually using (there were crash bugs discovered during its removal!). Because of these issues it was decided to join the vast majority of browsers and remove support for this format.
The developers also addressed several issues with toolchain construction and a number of annoying usability bugs.

Plans for how to improve printing support we made. Initially we intend to fix the existing haru based pdf generation using this to print via pdf and in future have correct css styled page paginated printing render output.

The perennial issue of javascript was discussed however, while efforts to improve the existing support are ongoing, our usage of the spidermonkey library continues to raise various challenges including platform support and API changes between versions.

Due to these issues it has been suggested that we might add support for using the duktape JS engine instead, initial results are promising but given the size of the task of implementing an additional javascript engine binding further investigation is necessary before making a commitment.

Amongst the other discussions the group has also agreed that we will once again apply to be a GSoC organisation for a single student with some very focused projects:
  • Improving our HTML5 parser (hubbub)
  • Improving the DOM library implementing missing functionality.
While neither of these projects are as fashionable as some of our previous proposals they are well defined enough that as a group we believe we could offer enough support to the student to make their experience a pleasurable one and get the resulting code reviewed and merged promptly.

This event was very successful with a great deal achieved, the project is much more likely to be in a good shape to release 3.1 by April now and the meeting has given the developers a much welcomed boost.

I would like to extend the groups thanks to Robert McQueen for letting us use the Collabora offices, Dor e Carrier for organising all the administrative things and to Vivek Dasmohapatra for coming out on his Sunday afternoon to let us back in after locking ourselves out.

12 October 2013

Lars Wirzenius: Moving repositories to

I'm moving all my git repositories from Gitorious and to my new Gitano instance at Gitano is a git server written by Daniel Silverstone, and it's wonderful. I will be converting my non-git repositories to git, on, later on.

17 December 2012

Lars Wirzenius: Obnam 1.3 (backup software) and other releases

I've just pushed out the release files for Obnam version 1.3, my backup application, as well as Larch, my B-tree library, and cliapp, my Python framework for command line applications. They are available via my home page ( Since Debian is frozen, I am not uploading packages to Debian, but .deb files are available from my personal apt repository for the intrepid. (I will be uploading to Debian again after the freeze. I am afraid I'm too lazy to upload to experimental, or do backports. Help is welcome!) From the Obnam NEWS file: Bug fixes for Obnam: NEWS for Larch: NEWS for cliapp:

5 November 2012

Vincent Sanders: Another NetSurf Developer Workshop

The NetSurf Developers - Bringing you alternative internet meme delivery since 2002
The weekend saw some of the NetSurf developers gather once again to do battle against the Red, wait. I mean plan and write code.

The successful event was once again kindly hosted by Collabora at their Cambridge office, the facilities remain as good as at the previous event and provided a comfortable environment in which to work.

Four developers managed to attend from around the UK John-Mark Bell, Vincent Sanders, Daniel Silverstone and Rob Kendrick. The turnout was a little lower than previous events, however Michael Drake managed to assist with some bug fixes remotely.

From Friday to Sunday afternoon we each managed to put in 24 hours of work consisting of almost 90 commits changing over 100 files and removing 10,000 lines of code.

Whiteboard with the 3.0 release tasks
The main theme of the event was consolidation ready for the 3.0 release. While not a glamorous target this is a major release for the project which we want to achieve soon, this requires the completion of numerous ongoing tasks (like finally removing the dependency of libxml) and fixing as many reported bugs as possible.

The Major things we achieved were:

Once the final usage of libXML is removed (from the hotlist code) NetSurf will become substantially smaller on several platforms as we will not have two separate parser implementations linked.

One big feature of the 3.0 release which was not originally on the roadmap is that of JavaScript. We initially intend to provide two builds of with and without the JavaScript interpreter compiled into NetSurf. This allows those on very small systems to continue to run NetSurf and those users who want a richer web experience to enjoy it.

Although JavaScript is a major new feature which is frequently requested the initial implementation will be incomplete. To complete the feature several thousand JavaScript to DOM interface binding functions must still be written. In addition it should be noted that we have yet to add dynamic layout or extensions such as Canvas or WebGL

We had a Raspberry Pi which was used to run RISC OS so we could examine the operation on this system.

The 2.9 edition as shipped works OK but is lacking the substantial progress made in the last six months.

The CI system build was run on the system and works well so we are reassured the 3.0 edition will provide an even better browsing experience.

The event was a great success overall and we are now very close to our 3.0 release which we hope to produce before Christmas.

6 August 2012

Vincent Sanders: Education is when you read the fine print. Experience is what you get if you don't.

Given my title I guess I just got a load of "experience" from Gandi. Previously I have written about building the NetSurf Continuous Integration (CI) server and my misjudgement of the resources it would require to be useful.

I contacted Gandi and they confirmed my suspicion that my only options to extend the VPS were to spend a great deal more money. The total spend would have been in excess of 300 per year to get a minimally satisfactory configuration.

So I contacted Mythic Beasts and they offered the NetSurf project a selection of deals they could not refuse. Once we decided on the right deal for us the system was in place, ready to use, within a morning.

Thanks to the generous open source project discount the offering from Mythic is almost double what Gandi were offering for less than half the price. I was, as previously concluded, dumb to go with Gandi in the first place when Mythic were an option.

Once the system was transferred to the shiny new server I went back to Gandi and asked how much my mistake of buying a years service for a single month worth of VPS service was going to cost. The reply was somewhat disappointing I was simply referred to section 8.1.2 of the contract (tl;dr We have your money now, tough luck, your problem). It would appear my mistake was going to cost me the full 114 I had paid.

I was somewhat disheartened at this turn of events but then Daniel Silverstone offered to take on the VPS if I could transfer it to his Gandi handle so he could administer it. this seemed like a good solution, at least the resource would be used and not wasted. Gandi response to this was initially promising but this is the final reply:

I'm really sorry to inform you that my supervisor refused the share transfer request to the other account. He told me that we do not transfer products either in those cases. I deeply apologize since I thought it was possible. I thank you for your confidence in Gandi, and hope that this occurrence does not deter you from continuing with us.
Now I must stress that Gandi are completely within their contractual rights to do this and are not obligated to provide any assistance to help make my blunder less costly to me, but they have firmly shown they have no willingness to be flexible in any way which means I know where I will not be spending my money in future.

Oh and then Pete from Mythic mentioned that they have a full refund and flexible policy on their services and we can always switch to the monthly billing rate and get a refund on the outstanding balance or move it or...

Basically my recommendation for an open source project looking for hosting, VPS or any network services has to be to go talk to the nice people at Mythic and steer clear of Gandi. Maybe in future all providers will realise that they are in a competitive market and certainly a little customer service flexibility might have made this posting much more about my mistake and not the attitude of the suppliers involved.

8 June 2012

Lars Wirzenius: Obnam 1.0 (backup software); a story in many words

tl;dr: Version 1.0 of Obnam, my snapshotting, de-duplicating, encrypting backup program is released. See the end of this announcement for the details. Where we see the hero in his formative years; parental influence From the very beginning, my computing life has involved backups. In 1984, when I was 14, my father was an independent telecommunications consultant, which meant he needed a personal computer for writing reports. He bought a Luxor ABC-802, a Swedish computer with a Z80 microprocessor and two floppy drives. My father also taught me how to use it. When I needed to save files, he gave me not one, but two floppies, and explained that I should store my files one one, and then copy them to the other one every now and then. Later on, over the years, I've made backups from a hard disk (30 megabytes!) to a stack of floppies, to a tape drive installed into a floppy interface (400 megabytes!), to a DAT drive, and various other media. It was always a bit tedious. The start of the quest; lengthy justification for NIH In 2004, I decided to do a full backup, by burning a copy of all my files onto CD-R disks. It took me most of the day. Afterwards, I sat admiring the large stack of disks, and realized that I would not ever do that again. I'm too lazy for that. That I had done it once was an aberration in the space-time continuum. Switching to DVD-Rs instead CD-Rs would reduce to the number of disks to burn, but not enough: it would still take a stack of them. I needed something much better. I had a little experience with tape drives, and that was enough to convince me that I didn't want them. Tape drives are expensive hardware, and the tapes also cost money. If the drive goes bad, you have to get a compatible one, or all your backups are toast. The price per gigabyte was coming down fast for hard drives, and it was clear that they were about to be very competitive with tapes for price. I looked for backup programs that I could use for disk based backups. rsync, of course, was the obvious choice, but there were others. I ended up doing what many geeks do: I wrote my own wrapper around rsync. There's hundred, possibly thousands, of such wrappers around the Internet. I also got the idea that doing a startup to provide online backup space would be a really cool thing. However, I didn't really do anything about that until 2007. More on that later. The rsync wrapper script I wrote used hardlinked directory trees to provide a backup history, though not in the smart way that backuppc does it. The hardlinks were wonderful, because they were cheap, and provided de-duplication. They were also quite cumbersome, when I needed to move my backups to a new disk the first time. It turned out that a lot of tools deal very badly with directory trees with large numbers of hardlinks. I also decided I wanted encrypted backups. This led me to find duplicity, which is a nice program that does encrypted backups, but I had issues with some of its limitations. To fix those limitations, I would have had to re-design and possibly re-implement the entire program. The biggest limitation was that it treated backups as full backup, plus a sequence of incremental backups, which were deltas against the previous backup. Delta based incrementals make sense for tape drives. You run a full backup once, then incremental deltas for every day. When enough time has passed since the full backup, you do a new full backup, and then future incrementals are based on that. Repeat forever. I decided that this makes no sense for disk based backups. If I already have backed up a file, there's no point in making me backup it again, since it's already there on the same hard disk. It makes even less sense for online backups, since doing a new full backup would require me to transmit all the data all over again, even though it's already on the server. The first battle I could not find a program that did what I wanted to do, and like every good NIHolic, I started writing my own. After various aborted attempts, I started for real in 2006. Here is the first commit message:
revno: 1
committer: Lars Wirzenius <>
branch nick: wibbr
timestamp: Wed 2006-09-06 18:35:52 +0300
  Initial commit.
wibbr was the placeholder name for Obnam until we came up with something better. We was myself and Richard Braakman, who was going to be doing the backup startup with me. We eventually founded the company near the end of 2006, and started doing business in 2007. However, we did not do very much business, and ran out of money in September 2007. We ended the backup startup experiment. That's when I took a job with Canonical, and Obnam became a hobby project of mine: I still wanted a good backup tool. In September 2007, Obnam was working, but it was not very good. For example, it was quite slow and wasteful of backup space. That version of Obnam used deltas, based on the rsync algorithm, to backup only changes. It did not require the user to do full and incremental backups manually, but essentially created an endless sequence of incrementals. It was possible to remove any generation, and Obnam would manage the deltas as necessary, keeping the ones needed for the remaining generations, and removing the rest. Obnam made it look as if each generation was independent of each other. The wasteful part was the way in which metadata about files was stored: each generation stored the full list of filenames and their permissions and other inode fields. This turned out to be bigger than my daily delta. The lost years; getting lost in the forest For the next two years, I did a little work on Obnam, but I did not make progress very fast. I changed the way metadata was stored, for example, but I picked another bad way of doing it: the new way was essentially building a tree of directory and file nodes, and any unchanged subtrees were shared between generations. This reduced the space overhead per generation, but made it quite slow to look up the metadata for any one file. The final battle; finding cows in the forest In 2009 I decided to leave Canonical and after that, my Obnam hobby picked up in speed again. Below is a table of the number of commits per year, from the very first commit (bzr log -n0 awk '/timestamp:/ print $3 ' sed 's/-.*//' uniq -c awk ' print $2, $1 ' tac):
2006 466
2007 353
2008 402
2009 467
2010 616
2011 790
2012 282
During most of 2010 and 2011 I was unemployed, and happily hacking Obnam, while moving to another country twice. I don't recommend that as a way to hack on hobby projects, but it worked for me. After Canonical, I decided to tackle the way Obnam stores data from a new angle. Richard told me about the copy-on-write (or COW) B-trees that btrfs uses, originally designed by Ohad Rodeh (see his paper for details), and I started reading about that. It turned out that they're pretty ideal for backups: each B-tree stores data about one generation. To start a new generation, you clone the previous generation's B-tree, and make any modifications you need. I implemented the B-tree library myself, in Python. I wanted something that was flexible about how and where I stored data, which the btrfs implementation did not seem to give me. (Also, I worship at the altar of NIH.) With the B-trees, doing file deltas from the previous generation no longer made any sense. I realized that it was, in any case, a better idea to store file data in chunks, and re-use chunks in different generations as needed. This makes it much easier to manage changes to files: with deltas, you need to keep a long chain of deltas and apply many deltas to reconstruct a particular version. With lists of chunks, you just get the chunks you need. The spin-off franchise; lost in a maze of dependencies, all alike In the process of developing Obnam, I have split off a number of helper programs and libraries: I have found it convenient to keep these split off, since I've been able to use them in other projects as well. However, it turns out that those installing Obnam don't like this: it would probably make sense to have a fat release with Obnam and all dependencies, but I haven't bothered to do that yet. The blurb; readers advised about blatant marketing The strong points of Obnam are, I think: Backups may be stored on local hard disks (e.g., USB drives), any locally mounted network file shares (NFS, SMB, almost anything with remotely Posix-like semantics), or on any SFTP server you have access to. What's not so strong is backing up online over SFTP, particularly with long round trip times to the server, or many small files to back up. That performance is Obnam's weakest part. I hope to fix that in the future, but I don't want to delay 1.0 for it. The big news; readers sighing in relief I am now ready to release version 1.0 of Obnam. Finally. It's been a long project, much longer than I expected, and much longer than was really sensible. However, it's ready now. It's not bug free, and it's not as fast as I would like, but it's time to declare it ready for general use. If nothing else, this will get more people to use it, and they'll find the remaining problems faster than I can do on my own. I have packaged Obnam for Debian, and it is in unstable, and will hopefully get into wheezy before the Debian freeze. I provide packages built for squeeze on my own repository, see the download page. The changes in the 1.0 release compared to the previous one: The future; not including winning lottery numbers I expect to get a flurry of bug reports in the near future as new people try Obnam. It will take a bit of effort dealing with that. Help is, of course, welcome! After that, I expect to be mainly working on Obnam performance for the foreseeable future. There may also be a FUSE filesystem interface for restoring from backups, and a continous backup version of Obnam. Plus other features, too. I make no promises about how fast new features and optimizations will happen: Obnam is a hobby project for me, and I work on it only in my free time. Also, I have a bunch of things that are on hold until I get Obnam into shape, and I may decide to do one of those things before the next big Obnam push. Where; the trail of an errant hacker I've developed Obnam in a number of physical locations, and I thought it might be interesting to list them: Espoo, Helsinki, Vantaa, Kotka, Raahe, Oulu, Tampere, Cambridge, Boston, Plymouth, London, Los Angeles, Auckland, Wellington, Christchurch, Portland, New York, Edinburgh, Manchester, San Giorgio di Piano. I've also hacked on Obnam in trains, on planes, and once on a ship, but only for a few minutes on the ship before I got seasick. Thank you; sincerely SEE ALSO

26 March 2012

Vincent Sanders: NetSurf Developer Workshop

NetSurf DevelopersOver the weekend we held the NetSurf developer workshop. The event was kindly hosted by Collabora at their Cambridge offices. The provided facilities were agreed to be excellent and contributed to the success of the event.

Five developers managed to attend from around the UK John-Mark Bell, Vincent Sanders, Michael Drake, Daniel Silverstone and Rob Kendrick. In addition James Shaw, one of the project founders, made a special appearance on Saturday.

Starting from Friday afternoon we each put in over 25 hours of actual useful work and made almost 170 commits changing over 350 files, added 10,000 new lines of code and altered another 18,000.

The main aim of the event was to make the transition from using libxml2 to our own libdom library for the browser DOM tree. This was done to improve the browsers performance and size when manipulating the DOM but also gives us the ability to extend the browsers features to include dynamic rendering and Javascript

We also took the opportunity to discuss and plan other issues including:
  • User interface message handling and translation.
  • User preference handling.
  • Toolchain support.
  • Disc caching.
  • Javascript binding
  • Electronic book content handler.
Rob tackled the first parts of the messages conversion from numerous separate files into a single easy to handle file which will in future allow for easier translation and reduce message proliferation.

We made decisions on the ongoing rework of user preference handling which will be implemented in future.

The decision on the toolchain was slightly changed to be that any core or library code (non frontend/toolkit specific parts) are required to conform to the C99 standard. Frontends are permitted to recommend and use whatever tools their maintainer selects but they cannot enforce those restrictions on core code. This issue is principly because the BeOS maintainer is compiling NetSurf with g++ 2.95 which is missing several important language features we wish to use.

Developers at workThe recurring issue of disc caching was raised again and we have come up with what we hope is a reasonably elegant solution to be implemented over the forthcoming months.

Now there is a suitable DOM to bind against, the existing Javascript engine support will be properly integrated and should result in basic script support before the 3.0 release. This support will remain a build time option so NetSurf can continue to be used on platforms where the interpreter is too resource intensive to be used.

A short discussion about the possibility of integrating a basic page based content handler for epub and mobi type documents was discussed and while the idea was well received no decisions on implementation were made.

Overall the event was a resounding success and we are left with only a small handful of regressions which appear straightforward to solve. We also have a clear set of decisions on what we need to do to improve the browser.

14 March 2012

Lars Wirzenius: New Obnam mailing list

Thanks to Daniel Silverstone, is now hosting a new mailing list for Obnam. See the mailman page for details. (I used to write my own mailing list software. I'm done with that. It's an awful hobby to have, and I don't even want to host any lists myself anymore. So I'm grateful for Daniel for doing this for me.)

28 October 2011

Lars Wirzenius: On the future of Linux distributions

Executive summary Debian should consider: Introduction I've taken a job with Codethink, as part of a team to develop a new embedded Linux system, called Baserock. Baserock is not a distribution as such, but deals with many of the same issues. I thought it might be interesting to write out my new thoughts related to this, since they might be useful for proper distributions to think about too. I'll hasten to add that many of these thoughts are not originally mine. I shamelessly adopt any idea that I think is good. The core ideas for Baserock come from Rob Taylor, Daniel Silverstone, and Paul Sherwood, my colleagues and bosses at Codethink. At the recent GNOME Summit in Montreal, I was greatly influenced by Colin Walters. This is also not an advertisment for Baserock, but since my of my current thinking come from that project, I'll discuss things in the context of Baserock. Finally, I'm writing this to express my personal opinion and thoughts. I'm not speaking for anyone else, least of all Codethink. On the package abstraction Baserock abandons the idea of packages for all individual programs. In the early 1990s, when Linux was new, and the number of packages in a distribution could be counted on two hands in binary, packages were a great idea. It was feasible to know at least something about every piece of software, and pick the exact set of software to install on a machine. It is still feasible to do so, but only in quite restricted circumstances. For example, picking the packages to install a DNS server, or an NFS server, or a mail server, by hand, without using meta packages or tasks (in Debian terminology), is still quite possible. On embedded devices, there's also usually only a handful of programs installed, and the people doing the install can be expected to understand all of them and decide which ones to install on each specific device. However, those are the exceptions, and they're getting rarer. For most people, manually picking software to install is much too tedious. In Debian, we've realised this a great many years ago, and developed meta packages (whose only purpose is to depend on other packages) and tasks (solves the same problem, but differently). These make it possible for a user to say "I want to have the GNOME desktop environment", and not have to worry about finding every piece that belongs in GNOME, and install that separately. For much of the past decade, computers have had sufficient hard disk space that it is no longer necessary to be quite so picky about what to install. A new cheap laptop will now typically come with at least 250 gigabytes of disk space. An expensive one, with an SSD drive, will have at least 128 gigabytes. A fairly complete desktop install uses less than ten gigabytes, so there's rarely a need to pick and choose between the various components. From a usability point of view, choosing from a list of a dozen or two options is much easier than from a list of thirty five thousand (the number of Debian packages as I write this). This is one reason why Baserock won't be using the traditional package abstraction. Instead, we'll collect programs into larger collections, called strata, which form some kind of logical or functional whole. So there'll be one stratum for the core userland software: init, shell, libc, perhaps a bit more. There'll be another for a development environment, one for a desktop environment, etc. Another, equally important reason, to move beyond packages is the problems caused by the combinatorial explosion of packages and versions. Colin Walters talks about this very well. When every system has a fairly unique set of packages, and versions of them, it becomes much harder to ensure that software works well for everyone, that upgrades work well, and that any problems get solved. When the number of possible package combinations is small, getting the interactions between various packages right is easier, QA has a much easier time to test all upgrade paths, and manual test coverage improves a lot when everyone is testing the same versions. Even debugging gets easier, when everyone can easily run the same versions. Grouping software into bigger collections does reduce flexibility of what gets installed. In some cases this is important: very constrainted embedded devices, for example, still need to be very picky about what software gets installed. However, even for them, the price of flash storage is low enough that it might not matter too much, anymore. The benefit of a simpler overall system may well outweigh the benefit of fine-grained software choice. Everything in git In Baserock, we'll be building everything from source in git. It will not be possible to build anything, unless the source is committed. This will allow us to track, for each binary blob we produce, the precise sources that were used to bulid it. We will also try to achieve something a bit more ambitious: anything that affects any bit in the final system image can be traced to files committed to git. This means tracking also all configuration settings for the build, and the whole build environment, in git. This is important for us so that we can reproduce an image used in the field. When a customer is deploying a specific image, and needs it to be changed, we want to be able to make the change with the minimal changes compared to the previous version of the image. This requires that we can re-create the original image, from source, bit for bit, so that when we make the actual change, only the changes we need to make affect the image. We will make it easy to branch and merge not just individual projects, but the whole system. This will make it easy to do large changes to the system, such as transitioning to a new version of GNOME, or the toolchain. Currently, in Debian, such large changes need to be serialised, so that they do not affect each other. It is easy, for example, for a GNOME transition to be broken by a toolchain transition. Branching and merging has long been considered the best available solution for concurrent development within a project. With Baserock, we want to have that for the whole system. Our build servers will be able to build images for each branch, without requiring massive hardware investment: any software that is shared between branches only gets built once. Launchpad PPAs and similar solutions provide many of the benefits of branching and merging on the system level. However, they're much more work than "git checkout -b gnome-3.4-transition". I believe that the git based approach will make concurrent development much more efficient. Ask me in a year if I was right. Git, git, and only git There are a lot of version control systems in active use. For the sake of simplicity, we'll use only git. When an upstream project uses something else, we'll import their code into git. Luckily, there are tools for that. The import and updates to it will be fully automatic, of course. Git is not my favorite version control system, but it's clearly the winner. Everything else will eventually fade away into obscurity. Or that's what we think. If it turns out that we're wrong about that, we'll switch to something else. However, we do not intend to have to deal with more than one at a time. Life's too short to use all possible tools at the same time. Tracking upstreams closely We will track upstream version control repositories, and we will have an automatic mechanism of building our binaries directly from git. This will, we hope, make it easy to follow closely upstream development, so that when, say, GNOME developers make commits, we want to be able to generate a new system image which includes those changes the same day, if not within minutes, rather than waiting days or weeks or months. This kind of closeness is greatly enhanced by having everything in version control. When upstream commits changes to their version control system, we'll mirror them automatically, and this then triggers a new system image build. When upstream makes changes that do not work, we can easily create a branch from any earlier commit, and build images off that branch. This will, we hope, also make it simpler to make changes, and give them back to upstream. Whenever we change anything, it'll be done in a branch, and we'll have system images available to test the change. So not only will upstream be able to easily get the change from our git repository, they'll also be easily verify, on a running system, that the change fixes the problem. Automatic testing, maybe even test driven development We will be automatically building system images from git commits for Baserock. This will potentially result in a very large number of images. We can't possibly test all of them manually, so we will implement some kind of automatic testing. The details of that are still under discussion. I hope to be able to start adding some test driven development to Baserock systems. In other words, when we are requested to make changes to the system, I want the specification to be provided as executable tests. This will probably be impossible in real life, but I can hope. I've talked about doing the same thing for Debian, but it's much harder to push through such changes in an established, large project. Solving the install, upgrade, and downgrade problems All mainstream Linux distributions are based on packages, and they all, pretty much, do installations and upgrades by unpacking packages onto a running system, and then maybe running some scripts from the packages. This works well for a completely idle system, but not so well on systems that are in active use. Colin Walters again talks about this. For installation of new software, the problem is that someone or something may invoke it before it is fully configured by the package's maintainer script. For example, a web application might unpack in such a way that the web server notices it, and a web browser may request the web app to run before it is configured to connect to the right database. Or a GUI program may unpack a .desktop file before the executable or its data files are unpacked, and a user may notice the program in their menu and start it, resulting in an error. Upgrades suffer from additonal problems. Software that gets upgraded may be running during the upgrade. Should the package manager replace the software's data files with new versions, which may be in a format that the old program does not understand? Or install new plugins that will cause the old version of the program to segfault? If the package manager does that, users may experience turbulence without having put on their seat belts. If it doesn't do that, it can't install the package, or it needs to wait, perhaps for a very long time, for a safe time to do the upgrade. These problems have usually been either ignored, or solved by using package specific hacks. For example, plugins might be stored in a directory that embeds the program's version number, ensuring that the old version won't see the new plugins. Some people would like to apply installs and upgrades only at shutdown or bootup, but that has other problems. None of the hacks solve the downgrade problem. The package managers can replace a package with an older version, and often this works well. However, in many cases, any package maintainer scripts won't be able to deal with downgrades. For example, they might convert data files to a new format or name or location upon upgrades, but won't try to undo that if the package gets downgraded. Given the combinatorial explosion of package versions, it's perhaps just as well that they don't try. For Baserock, we absolutely need to have downgrades. We need to be able to go back to a previous version of the system if an upgrade fails. Traditionally, this has been done by providing a "factory reset", where the current version of the system gets replaced with whatever version was installed in the factory. We want that, but we also want to be able to choose other versions, not just the factory one. If a device is running version X, and upgrades to X+1, but that version turns out to be a dud, we want to be able to go back to X, rather than all the way back to the factory version. The approach we'll be taking with Baserock relies on btrfs and subvolumes and snapshots. Each version of the system will be installed in a separate subvolume, which gets cloned from the previous version, using copy-on-write to conserve space. We'll make the bootloader be able to choose a version of the system to boot, and (waving hands here) add some logic to be able to automatically revert to the previous version when necessary. We expect this to work better and more reliably than the current package based one. Making choices Debian is pretty bad at making choices. Almost always, when faced with a need to choose between alternative solutions for the same problem, we choose all of them. For example, we support pretty much every init implementation, various implementations of /bin/sh, and we even have at least three entirely different kernels. Sometimes this is non-choice is a good thing. Our users may need features that only one of the kernels support, for example. And we certainly need to be able to provide both mysql and postresql, since various software we want to provide to our uses needs one and won't work with the other. At other times, the inability to choose causes trouble. Do we really need to support more than one implemenation of /bin/sh? By supporting both dash and bash for that, we double the load on testing and QA, and introduce yet another variable to deal with into any debugging situation involving shell scripts. Especially for core components of the system, it makes sense to limit the flexibility of users to pick and choose. Combinatorial explosion d j vu. Every binary choice doubles the number of possible combinations that need to be tested and supported and checked during debugging. Flexibility begets complexity, complexity begets problems. This is less of a problem at upper levels of the software stack. At the very top level, it doesn't really matter if there are many choices. If a user can freely choose between vi and Emacs, and this does not add complexity at the system level, since nothing else is affected by that choice. However, if we were to add a choice between glibc, eglibc, and uClibc for the system C library, then everything else in the system needs to be tested three times rather than once. Reducing the friction coefficient for system development Currently, a Debian developer takes upstream code, adds packaging, perhaps adds some patches (using one of several methods), builds a binary package, tests it, uploads it, and waits for the build daemons and the package archive and user-testers to report any problems. That's quite a number of steps to go through for the simple act of adding a new program to Debian, or updating it to a new version. Some of it can be automated, but there's still hoops to jump through. Friction does not prevent you from getting stuff done, but the more friction there is, the more energy you have to spend to get it done. Friction slows down the crucial hack-build-test cycle of software development, and that hurts productivity a lot. Every time a developer has to jump through any hoops, or wait for anything, he slows down. It is, of course, not just a matter of the number of steps. Debian requires a source package to be uploaded with the binary package. Many, if not most, packages in Debian are maintained using version control systems. Having to generate a source package and then wait for it to be uploaded is unnecessary work. The build daemon could get the source from version control directly. With signed commits, this is as safe as uploading a tarball. The above examples are specific to maintaining a single package. The friction that really hurts Debian is the friction of making large-scale changes, or changes that affect many packages. I've already mention the difficulty of making large transitions above. Another case is making policy changes, and then implementing them. An excellent example of that is in Debian is the policy change to use /usr/share/doc for documentation, instead of /usr/doc. This took us many years to do. We are, I think, perhaps a little better at such things now, but even so, it is something that should not take more than a few days to implement, rather than half a decade. On the future of distributions Occasionally, people say things like "distributions are not needed", or that "distributions are an unnecessary buffer between upstream developers and users". Some even claim that there should only be one distribution. I disagree. A common view of a Linux distribution is that it takes some source provided by upstream, compiles that, adds an installer, and gives all of that to the users. This view is too simplistic. The important part of developing a distribution is choosing the upstream projects and their versions wisely, and then integrating them into a whole system that works well. The integration part is particularly important. Many upstreams are not even aware of each other, nor should they need to be, even if their software may need to interact with each other. For example, not every developer of HTTP servers should need to be aware of every web application, or vice versa. (It they had to be, it'd be a combinatorial explosion that'd ruin everything, again.) Instead, someone needs to set a policy of how web apps and web servers interface, what their common interface is, and what files should be put where, for web apps to work out of the box, with minimal fuss for the users. That's part of the integration work that goes into a Linux distribution. For Debian, such decisions are recorded in the Policy Manual and its various sub-policies. Further, distributions provide quality assurance, particularly at the system level. It's not realistic to expect most upstream projects to do that. It's a whole different skillset and approach that is needed to develop a system, rather than just a single component. Distributions also provide user support, security support, longer term support than many upstreams, and port software to a much wider range of architectures and platforms than most upstreams actively care about, have access to, or even know about. In some cases, these are things that can and should be done in collaboration with upstreams; if nothing else, portability fixes should be given back to upstreams. So I do think distributions have a bright future, but the way they're working will need to change.