Planet ALUG

October 16, 2014

Steve Engledow (stilvoid)



OggCamp was fantastic. If I can remember all the talks I went to I'll do a brief write up. The event certainly left me with a few little ideas for things to write and do.

Down with dynamic things!

One small example is that I've rewritten the build script for this blog. No more scripted generation of the final HTML; I just wget -m the development server and that's everything built. Then it's all just served up as static content through nginx. Simples and I don't know why I didn't think of just snapshotting it like that before.


I've reached a point in my career now where I find myself wanting to create and present slide decks. WTF?

I'm still writing code fairly regularly but there's so much other stuff I spend my time doing that I'm not even sure I can account for. It still feels important.


I think I'm going to buy a Pebble to wean myself off the phone-checking habit that I've developed over the years.

Relatedly, I wrote this post on my phone. It wasn't nearly as painful as I'd expected.

by Steve Engledow ( at October 16, 2014 12:05 AM

October 09, 2014

Wayne Stallwood (DrJeep)

Hosting Update2

Well after a year the SD card on the Raspberry Pi has failed, I noticed /var was unhappy when I tried to apply the recent Bash updates. Attempts at repair only made things worse and I suspect there is some physical issue. I had minimised writes with logs in tmpfs and the frequently updated weather site sat in tmpfs too..logging to remote systems etc. So not quite sure what happened. Of course this is all very inconvenient when your kit lives in another country, so at some point I guess I will have to build a new SD card and ship it out...for now we are back on Amazon EC2...yay for the elastic cloud \o/

October 09, 2014 09:31 PM

Chris Lamb

London—Paris—London 2014

I've wanted to ride to Paris for a few months now but was put off by the hassle of taking a bicycle on the Eurostar, as well having a somewhat philosophical and aesthetic objection to taking a bike on a train in the first place. After all, if one already is possession of a mode of transport...

My itinerary was straightforward:

Friday 12h00
London → Newhaven
Friday 23h00
Newhaven → Dieppe (ferry)
Saturday 04h00
Dieppe → Paris
Saturday 23h00
Sunday 07h00
Paris → Dieppe
Sunday 18h00
Dieppe → Newhaven (ferry)
Sunday 21h00
Newhaven → Peacehaven
Sunday 23h00
Monday 07h00
Peacehaven → London

Packing list

Not pictured:

Day 1: London → Newhaven

Tower Bridge.

Many attempt to go from Tower Bridge → Eiffel Tower (or Marble Arch → Arc de Triomphe) in less than 24 hours. This would have been quite easy if I had left a couple of hours later.

Fanny's Farm Shop, Merstham, Surrey.

Plumpton, East Sussex.

West Pier, Newhaven.

Leaving Newhaven on the 23h00 ferry.

Day 2: Dieppe → Paris

Beauvoir-en-Lyons, Haute-Normandie.

Sérifontaine, Picardie.

La tour Eiffel, Paris.

Champ de Mars, Paris.

Pont de Grenelle, Paris.

Day 3: Paris → Dieppe

Cormeilles-en-Vexin, Île-de-France.

Gisors, Haute-Normandie.

Paris-Brest, Gisors, Haute-Normandie.

Wikipedia: This pastry was created in 1910 to commemorate the Paris–Brest bicycle race begun in 1891. Its circular shape is representative of a wheel. It became popular with riders on the Paris–Brest cycle race, partly because of its energizing high caloric value, and is now found in pâtisseries all over France.

Gournay-en-Bray, Haute-Normandie.

Début de l'Avenue Verte, Forges-les-Eaux, Haute-Normandie.

Mesnières-en-Bray, Haute-Normandie.

Dieppe, Haute-Normandie.

«La Mancha».

Day 4: Peacehaven → London

Peacehaven, East Sussex.

Highbrook, West Sussex.

London weather.

588.17 km
Pedal turns

My only non-obvious tips would be to buy a disposable blanket in the Newhaven Co-Op to help you sleep on the ferry. In addition, as the food on the ferry is good enough you only need to get to the terminal one hour before departure, avoiding time on your feet in unpicturesque Newhaven.

In terms of equipment, I would bring another light for the 4AM start on «L'Avenue Verte» if only as a backup and I would have checked I could arrive at my Parisian Airbnb earlier in the day - I had to hang around for five hours in the heat before I could have a shower, properly relax, etc.

I had been warned not to rely on being able to obtain enough water en route on Sunday but whilst most shops were indeed shut I saw a bustling tabac or boulangerie at least once every 20km so one would never be truly stuck.

Route-wise, the surburbs of London and Paris are both equally dismal and unmotivating and there is about 50km of rather uninspiring and exposed riding on the D915.

However, «L'Avenue Verte» is fantastic even in the pitch-black and the entire trip was worth it simply for the silent and beautiful Normandy sunrise. I will be back.

October 09, 2014 05:19 PM

October 03, 2014

Ben Francis

What is a Web App?

What is a web app? What is the difference between a web app and a web site? What is the difference between a web app and a non-web app?

In terms of User Experience there is a long continuum between “web site” and “web app” and the boundary between the two is not always clear. There are some characteristics that users perceive as being more “app like” and some as more “web like”.

The presence of web browser-like user interface elements like a URL bar and navigation controls are likely to make a user feel like they’re using a web site rather than an app for example, whereas content which appears to run independently of the browser feels more like an app. Apps are generally assumed to have at least limited functionality without an Internet connection and tend to have the concept of residing in a self-contained way on the local device after being “installed”, rather than being navigated to somewhere on the Internet.

From a technical point of view there is in fact usually very little difference between a web site and a web app. Different platforms currently deal with the concept of “web apps” in all sorts of different, incompatible ways, but very often the main difference between a web site and web app is simply the presence of an “app manifest”. The app manifest is a file containing a collection of metadata which is used when “installing” the app to create an icon on a homescreen or launcher.

At the moment pretty much every platform has its own proprietary app manifest format, but the W3C has the beginnings of a proposed specification for a standard “Manifest for web applications” which is starting to get traction with multiple browser vendors.

Web Manifest – Describing an App

Below is an example of a web app manifest following the proposed standard format.

  "name": "My App",
  "icons": [{
    "src": "/myapp/icon.png",
    "sizes": "64x64",
    "type": "image/png"
  "start_url": "/myapp/index.html"

The manifest file is referenced inside the HTML of a web page using a link relation. This is cool because with this approach a web app doesn’t have to be distributed through a centrally controlled app store, it can be discovered and installed from any web page.

<!DOCTYPE html>
    <title>My App - Welcome</title>
    <link rel="manifest" href="manifest.json">
    <meta name="application-name" content="My App">
    <link rel="icon" sizes="64x64" href="icon.png">

As you can see from the example, these basic pieces of metadata which describe things like a name, an icon and a start URL are not that interesting in themselves because these things can already be expressed in HTML in a web standard way. But there are some other other proposed properties which could be much more interesting.

Display Modes – Breaking out of the Browser

We said above that one thing that makes a web app feel more app like is when it runs outside of the browser, without common browser UI elements like the URL bar and navigation controls. The proposed “display” property of the manifest allows authors of web content which is designed to function without the need for these UI elements to express that they want their content to run outside of the browser.

  "name": "My App",
  "icons": [{
    "src": "/myapp/icon.png",
    "sizes": "64x64",
    "type": "image/png"
  "start_url": "/myapp/index.html"
  "scope": "/myapp"
  "display": "standalone"

The proposed display modes are “fullscreen”, “standalone”, “minimal-ui” and “browser”. The “browser” display mode opens the content in the user agent’s conventional method (e.g. a browser tab), but all of the other display modes open the content separate from the browser, with varying levels of browser UI.

There’s also a proposed “orientation” property which allows the content author to specify the default orientation (i.e. portrait/landscape) of their content.

App Scope – A Slice of the Web

In order for a web app to be treated separately from the rest of the web, we need to be able to define which parts of the web are part of the app, and which are not. The proposed “scope” property of the manifest defines the URL scope to which the manifest applies.

By default the scope of a web app is anything from the same origin as its manifest, but a single origin can also be sliced up into multiple apps or into app and non-app content.

Below is an example of a web app manifest with a defined scope.

  "name": "My App",
  "icons": [{
    "src": "/myapp/icon.png",
    "sizes": "64x64",
    "type": "image/png"
  "start_url": "/myapp/index.html"
  "scope": "/myapp"

From the user’s point of view they can browse around the web, seamlessly navigating between web apps and web sites until they come across something they want to keep on their device and use often. They can then slice off that part of the web by “bookmarking” or “installing” it on their device to create an icon on their homescreen or launcher. From that point on, that slice of the web will be treated separately from the browser in its own “app”.

Without a defined scope, a web app is just a web page opened in a browser window which can then be navigated to any URL. If that window doesn’t have any browser-like navigation controls or a URL bar then the user can get stranded at a dead on the web with no way to go back, or worse still can be fooled into thinking that a web page they thought was part of a web app they trust is actually from another, malicious, origin.

The web browser is like a catch-all app for browsing all of the parts of the web which the user hasn’t sliced off to use as a standalone app. Once a web app is registered with the user agent as managing a defined slice of the web, the user can seamlessly link into and out of installed web apps and the rest of the web as they please.

Service Workers – Going Offline

We said above that another characteristic users often associate with “apps” is their ability to work offline, in the absence of a connection to the Internet. This is historically something the web has done pretty badly at. AppCache was a proposed standard intended for this purpose, but there are many common problems and limitations of that technology which make it difficult or impractical to use in many cases.

A new, much more versatile, proposed standard is called Service Workers. Service Workers allow a script to be registered as managing a slice of the web, even whilst offline, by intercepting HTTP requests to URLs within a specified scope. A Service Worker can keep an offline cache of web resources and decide when to use the offline version and when to fetch a new version over the Internet.

The programmable nature of Service Workers make them an extremely versatile tool in adding app-like capabilities to web content and getting rid of the notion that using the web requires a persistent connection to the Internet. Service Workers have lots of support from multiple browser vendors and you can expect to see them coming to life soon.

The proposed “service_worker” property of the manifest allows a content author to define a Service Worker which should be registered with a specified URL scope when a web app is installed or bookmarked on a device. That means that in the process of installing a web app, an offline cache of web resources can be populated and other installation steps can take place.

Below is our example web app manifest with a Service Worker defined.

  "name": "My App",
  "icons": [{
    "src": "/myapp/icon.png",
    "sizes": "64x64",
    "type": "image/png"
  "start_url": "/myapp/index.html"
  "scope": "/myapp"
  "service_worker": {
    "src": "app.js",
    "scope": "/myapp"

Packages – The Good, the Bad and the Ugly

There’s a whole category of apps which many people refer to as “web apps” but which are delivered as a package of resources to be downloaded and installed locally on a device, separate from the web. Although these resources may use web technologies like HTML, CSS and Javascript, if those resources are not associated with real URLs on the web, then in my view they are by definition not part of a web app.

The reason this approach is commonly taken is that it allows operating system developers and content authors to side-step some of the current shortcomings of the web platform. Packaging all of the resources of an app into a single file which can be downloaded and installed on a device is the simplest way to solve the offline problem. It also has the convenience that the contents of that package can easily be reviewed and cryptographically signed by a trusted party in order to safely give the app privileged access to system functions which would currently be unsafe to expose to the web.

Unfortunately the packaged app approach misses out on many of the biggest benefits of the web, like its universal and inter-linked nature. You can’t hyperlink into a packaged app, and providing an updated version of the app requires a completely different mechanism to that of web content.

We have seen above how Service Workers hold some promise in finally solving the offline problem, but packages as a concept may still have some value on the web. The proposed “Packaging on the Web” specification is exploring ways to take advantage of some of the benefits of packages, whilst retaining all the benefits of URLs and the web.

This specification does not explore a new security model for exposing more privileged APIs to the web however, which in my view is the single biggest unsolved problem we now have left on the web as a platform.


In conclusion, a look at some of the latest emerging web standards tells us that the answer to the question “what is a web app?” is that a web app is simply a slice of the web which can be used separately from the browser.

With that in mind, web authors should design their content to work just as well inside and outside the browser and just as well offline as online.

Packaged apps are not web apps and are always a platform-specific solution. They should only be considered as a last resort for apps which need access to privileged functionality that can’t yet be safely exposed to the web. New web technologies will help negate the need for packages for offline functionality, but packages as a concept may still have a role on the web. A security model suitable for exposing more privileged functionality to the web is one of the last remaining unsolved challenges for the web as a platform.

The web is the biggest ecosystem of content that exists, far bigger than any proprietary walled garden of curated content. Lots of cool stuff is possible using web technologies to build experiences which users would consider “app like”, but creating a great user experience on the web doesn’t require replicating all of the other trappings of proprietary apps. The web has lots of unique benefits over other app platforms and is unrivalled in its scale, ubiquity, openness and diversity.

It’s important that as we invent cool new web technologies we remember to agree on standards for them which work cross-platform, so that we don’t miss out on these unique benefits.

The web as a platform is here to stay!

by tola at October 03, 2014 04:50 PM

September 26, 2014

Mick Morgan

CVE-2014-6271 bash vulnerability

Guess what I found in trivia’s logs this morning? – - [25/Sep/2014:10:48:13 +0100] “GET /cgi-sys/defaultwebpage.cgi HTTP/1.0″ 404 345 “-” “() { :;}; /bin/ping -c 1″

I’ll bet a lot of cgi scripts are being poked at the moment.

Check your logs guys. A simple grep “:;}” access.log will tell you all you need to know.

(Update 27 September)

Digital Ocean, the company I use to host my Tor node and tails/whonix mirrors, has posted a useful note about the vulnerability. And John Leyden at El Reg posted about the problem here. Leyden’s article references some of the more authoritative discussions so I won’t repeat the links here.

All my systems were vulnerable, but of course have now been patched. However, the vulnerability has existed in bash for so long that I can’t help but feel deeply uneasy even though, as Michal Zalewski (aka lcamtuf) notes in his blog:

PS. As for the inevitable “why hasn’t this been noticed for 15 years” / “I bet the NSA knew about it” stuff – my take is that it’s a very unusual bug in a very obscure feature of a program that researchers don’t really look at, precisely because no reasonable person would expect it to fail this way. So, life goes on.

by Mick at September 26, 2014 11:38 AM

September 18, 2014

Jonathan McDowell

Automatic inline signing for mutt with RT

I spend a surprising amount of my time as part of keyring-maint telling people their requests are badly formed and asking them to fix them up so I can actually process them. The one that's hardest to fault anyone on is that we require requests to be inline PGP signed (i.e. the same sort of output as you get with "gpg --clearsign"). That's because RT does various pieces of unpacking[0] of MIME messages that mean that a PGP/MIME signatures that have passed through it are no longer verifiable. Daniel has pointed out that inline PGP is a bad idea and got as far as filing a request that RT handle PGP/MIME correctly (you need a login for that but there's a generic read-only one that's easy to figure out), but until that happens the requirement stands when dealing with Debian's RT instance. So today I finally added the following lines to my .muttrc rather than having to remember to switch Mutt to inline signing for this one special case:

send-hook . "unset pgp_autoinline; unset pgp_autosign"
send-hook "set pgp_autosign; set pgp_autoinline"

i.e. by default turn off auto inlined PGP signatures, but when emailing anything at turn them on.

(Most of the other things I tell people to fix are covered by the replacing keys page; I advise anyone requesting a key replacement to read that page. There's even a helpful example request template at the bottom.)

[0] RT sticks a header on the plain text portion of the mail, rather than adding a new plain text part for the header if there are multiple parts (this is something Mailman handles better). It will also re-encode received mail into UTF-8 which I can understand, but Mutt will by default try to find an 8 bit encoding that can handle the mail, because that's more efficient, which tends to mean it picks latin1.

Update: Apparently Mutt in Jessie and beyond doesn't have the pgp_autosign option; you want crypt_autosign instead (and maybe crypt_autopgp but that defaults to yes so unless you've configured your setup to do S/MIME by default you should be fine). Thanks to Luca Capello for pointing this out.

September 18, 2014 10:39 AM

September 12, 2014

Jonathan McDowell

Back from DebConf 14

I previously forgot to mention that I was planning to attend DebConf14, having missed DebConf13. This year the conference was held in Portland, OR. This is a city I've been to many times before, and enjoy, but I hadn't spent any time wandering around its city centre as a pedestrian. I have to say I really prefer DebConfs that are held in middle of city. It always seems a bit of a shame to travel some distance to somewhere new and spend all the time there in a conference venue. Plus these days I have the added lure of going out and playing Ingress in a new location. DebConf14 didn't disappoint in these respects; the location was super easy to get to from the airport via public transportation, all of the evening social events were within reasonable walking distance (I'll tend to default to walking when possible) and the talk venue/accommodation were close to each other and various eating + drinking options. Throw in the fact at Portland managed to produce some excellent weather (modulo my Ingress session on the last Saturday morning, when rained on me) and it's impossible to fault the physicalities of DebConf this year.

This year the conference format was a bit different; previous years have had a week long DebConf before the week of the conference itself. This year went for a 9 day talk schedule (Saturday -> Sunday) with various gaps of hacking time interspersed. I've found it hard to justify a full two weeks away in the past, so this setup worked a lot better from my viewpoint. Also I rarely go to DebConf with a predetermined list of things to do; the stuff I work on naturally falls out of talks I attend and informal discussions I have. Having hack time throughout the conference helped me avoid feeling I was having to trade off hacking vs talks.

Naturally enough a lot of my involvement at DebConf was around OpenPGP. Gunnar and I spent a fair bit of time getting Daniel up to speed with the keyring-maint team (Gunnar more than I, I'll confess). We finally set a hard timeframe for freeing Debian of older 1024 bit keys. I was introduced to the Gnuk, which is a particularly interesting piece of open specification hardware with a completely Free software stack on top if it that implements the OpenPGP smartcard spec. Currently it's limited to 2K keys but it's hoped that 4K support can be added (and I ended up spending a couple of hours after the closing talk hacking on the source and seeing how much needs to change for 4K support, aided by the very patient Niibe). These are the sort of things that really benefit from the face time that DebConf offers to the Debian project. I've said it before, but I think it's worth saying again: Debian is a bit like a huge telecommuting organization and it's my opinion that any such organization should try and ensure its members actually spend some time together on a regular basis. It improves the ability to work remotely a hell of a lot if you can actually put a face to the entity you're emailing / IRCing and have some sort of idea where they're coming from because you've spent some time with them, whether that's in talks or over dinner or just casual hallway chats.

For once I also found myself considering alternative employment while at DebConf and it was incredibly useful to be able to have various conversations with both old friends and people who were there with an eye on recruitment. Thanks to all those whose ears I bent about the subject (and more on the outcome in a future post). Thank you also to the many people involved with the organization of DebConf; I've been on the periphery a few times over the years and it's given me a glimpse into the amount of hard work all of the volunteers (be they global team, local organizing team, video team or just random volunteers) put into making DebConf one of my must-attend yearly conferences. If you're at all involved in Debian and haven't attended I strongly urge you to do so - I'll see you all next year at DebConf15 in Heidelberg!

September 12, 2014 02:03 PM

September 05, 2014

Steve Engledow (stilvoid)

Lessons learned

by Steve Engledow ( at September 05, 2014 08:51 AM

August 13, 2014

Mick Morgan

net neutrality

My apologies that this is a few weeks late – but it still bears posting. John Oliver at HBO gave the best description of the net neutrality argument I have seen so far.

Following that broadcast, the FCC servers were, rather predictably, overwhelmed by the outraged response from the trolls that Oliver set loose.

Unfortunately, as John Naughton reports in the Observer, the FCC are unlikely to be moved by that.

by Mick at August 13, 2014 08:46 PM

August 07, 2014

Ben Francis

Building the Firefox Browser for Firefox OS

Re-posted from Mozilla Hacks.

Boot to Gecko

As soon as the Boot to Gecko (B2G) project was announced in July 2011 I knew it something I wanted to contribute to. I’d already been working on the idea of a browser based OS for a while but it seemed Mozilla had the people, the technology and the influence to build something truly disruptive.

At the time Mozilla weren’t actively recruiting people to work on B2G, the team still only consisted of the four co-founders and the project was little more than an empty GitHub repository. But I got in touch the day after the announcement and after conversations with Chris, Andreas and Mike over Skype and a brief visit to Silicon Valley, I somehow managed to convince them to take me on (initially as a contractor) so I could work on the project full time.

A Web Browser Built from Web Technologies

On my first day Chris Jones told me “The next, highest-priority project is a very basic web browser, just a URL bar and back button basically.”


Chris and his bitesize browser, Taipei, December 2011

The team was creating a prototype smartphone user interface codenamed “Gaia”, built entirely with web technologies. Partly to prove it could be done, but partly to find the holes in the web platform that made it difficult and fill those holes with new Web APIs. I was asked to work on the first prototypes of a browser app, a camera app and a gallery app to help find some of those holes.

You might wonder why a browser-based OS needs a browser app at all, but the thinking for this prototype was that if other smartphone platforms had a browser app, then B2G would need one too.

The user interface of the desktop version of Firefox is written in highly privileged “chrome” code using the XUL markup language. On B2G it would need to be written in “content” using nothing but HTML, CSS and JavaScript, just like all the other apps. That would present some interesting challenges.

In the beginning, there was an <iframe>

It all started with a humble iframe, a text input for the URL bar and a go button, in fact you can see the first commit here. When you clicked the go button, it set the src attribute of the iframe to the contents of the text input, which caused the iframe to load the web page at that URL.


First commit, November 2011

The first problem with trying to build a web browser using an iframe is that the same-origin policy in JavaScript prevents you accessing just about any information about what’s going on inside it if the content comes from a different origin than the browser itself. In particular, it’s not possible to access the contentWindow property and all of the information that gives access to. This policy exists for good reasons so in order to build a fully functional web browser we would have to figure out a way for a privileged web app to safely poke holes in that cross-origin boundary to get just enough information to do its job, but without creating serious security vulnerabilities or compromising the user’s privacy.

Another problem we came across quite quickly was that many web authors will go to great lengths to prevent their web site being loaded inside an iframe in order to prevent phishing attacks. A web server can send an X-Frame-Options HTTP response header instructing a user agent to simply not render the content, and there are also a variety of techniques for “framebusting” where a web site will actively try to break out of an iframe and load itself in the parent frame instead.

It was quickly obvious that we weren’t going to get very far building a web browser using web technologies without evolving the web technologies themselves.

The Browser API

I met Justin Lebar at the first B2G work week in Taipei in December 2011. He was tasked with modifying Gecko to make the browser app on Boot to Gecko possible. To me Gecko was (and largely still is) a giant black box of magic spells which take the code I write and turn it into dancing images on the screen. I needed a wizard who had a grasp on some of these spells, including a particularly strong spell called Docshell which only the most practised of wizards dare peer into.


Justin at the first B2G Work Week in Taipei, December 2011

When I told Justin what I needed he made the kinds of sounds a mechanic makes when you take your car in for what you think is a simple problem but turns out costing the price of a new car. Justin had a better idea than I did as to what was needed, but I don’t think either of us realised the full scale of the task at hand.

With the adding of a simple boolean “mozbrowser” attribute to the HTML iframe element in Gecko, the Browser API was born. I tried adding features to the browser app and every time I found something that wasn’t possible with current web technologies, I went back to Justin to get him to cast a new magic spell.

There were easier approaches we could have taken to build the browser app. We could have added a mechanism to allow the browser to inject scripts into the iframe and communicate freely with the content inside, but we wanted to provide a safe API which anyone could use to build their own browser app and this approach would be too risky. So instead we built an explicit privileged API into the DOM to create a new class of iframe which could one day become a new standard HTML tag.

Keeping the Web Contained

The first thing we did was to try to trick web pages loaded inside an iframe into thinking they were not in fact inside an iframe. At first we had a crude solution which just ignored X-Frame-Options headers for iframes in whitelisted domains that had the mozbrowser attribute. That’s when we discovered that some web sites are quite clever at busting out of iframes. In the end we had to take other measures like making sure pointed at the iframe rather than its parent so a web site couldn’t detect that it had a parent, and eventually also run every browser tab in its own system process to completely isolate them from each other.

Once we had the animal that is the web contained, we needed to poke a few air holes to let it breathe. There’s some information we need to let out of the iframe in the form of events: when the location, title or icon of a web page changes (locationchange, titlechange and iconchange); when a page starts and finishes loading (loadstart, loadend) and when the security characteristics of the currently loaded page changes (securitychange). This all allows us to keep the address bar and title bar up to date and show a progress indicator.

The browser app needs to be able to navigate the iframe by telling it to goBack(), goForward(), stop() and reload(). We also need to be able to explicitly ask for information like characteristics of the session history (getCanGoBack(), getCanGoForward()) to determine which navigation buttons to display.

With these basics in place it was possible to build a simple functional browser app.

The Prototype

The Gaia project’s first UX designer was Josh Carpenter. At an intensive work week in Paris the week before Mobile World Congress in February 2012, Josh created UI mockups for all the basic features of a smartphone, including a simple browser, and we built a prototype to those designs.


Josh and me plotting over a beer in Paris.


The prototype browser app could navigate web content, keep it contained and display basic information about the content being viewed. This would be the version demonstrated at MWC in Barcelona that year.


Simple browser demo for Mobile World Congress, February 2012

Building a Team

At a work week in Qualcomm’s offices in San Diego in May 2012 I was able to give a demo of a slightly more advanced basic browser web app running inside Firefox on the desktop. But it was still very basic. We needed a team to start building something good enough that we could ship it on real devices.


“Browser Inception”, San Diego May 2012

San Diego was also where I first met Dale Harvey, a brave Scotsman who came on board to help with Gaia. His first port of call was to help out with the browser app.


Dale Getting on Board in San Diego, May 2012

One of the first things Dale worked on was creating multiple tabs in the browser and even adding a screenshotting spell to the Browser API to show thumbnails of browser tabs (I told you he was brave).

By this time we had also started to borrow Larissa Co, a brilliant designer from the Firefox team, to work on the interaction design and Patryk Adamczyk, formerly of RIM, to work on the visual design for the browser on B2G. That was when it started to look more like a Firefox browser.


Early UI Mockup, July 2012

Things that Pop Up

Web pages like to make things pop up. For a start they like to alert(), prompt() or confirm() things with you. Sometimes they like to open() a new browser window (and close() them again), open a link in a _blank window, ask you for a password, ask for your permission to do something, ask you to select an option from a menu, open a context menu or confirm re-sending the contents of a form.


An alert(), version 1.0

All of this required new events in the Browser API, which meant more spells for Justin to cast.

Scroll, Pan and Zoom

Moving around web pages on web devices works a little differently from on the desktop. Rather than scroll bars or a scroll wheel on a mouse it uses touch input and a system called Asynchronous Pan and Zoom to allow the user to pan around a web page by dragging it and scrolling it using “kinetic scrolling” which feels like it has some physics to it.

The first implementation of kinetic scrolling was written in JavaScript by Frenchman and Gaia leader Vivien Nicolas, specifically for Gaia, but it would later be written in a cross-platform way in Gecko to unify the code used on B2G and Android.

One of the trickier interactions to get right was that we wanted the address bar to hide as you scrolled down the page in order to make more room for content, then show again when you scroll back to the top of the page.

This required adding asyncscroll events which tapped directly into the Asynchronous Pan and Zoom code so that the browser knew not only when the user directly manipulated the page, but how much it scrolled based on physics, asynchronously from the user’s interaction.

Storing Stuff

One of the most loved features of Firefox is the “Awesomebar”, a combined address bar, search bar (and on mobile, title bar) which lets you quickly get to the content you’re looking for. You type a few characters and immediately start to see matching web pages from your browsing history, ranked by a “frecency” algorithm.

On the desktop and on Android all of this data is stored in the “Places” database as part of privileged “chrome” code. In order to implement this feature in B2G we would need to use the local storage capabilities of the web, and for that we chose IndexedDB. We built a Places database in IndexedDB which would store all of the “places” a user visits on the web including their URL, title and icon, and store all the times the user visited that page. It would also be used to store the users bookmarks and rank top sites by “frecency”.


Awesomebar, version 1.0

Clearing Stuff

As you browse around the web Gecko also stores a bunch of data about the places you’ve been. That can be cookies, offline pages, localStorage, IndexedDB databases and all sorts of other bits of data. Firefox browsers provide a way for you to clear all of this data, so methods needed to be added to the Browser API to allow this data to be cleared from the browser settings in B2G.


Browser settings, version 1.0

Handling Crashes

Sometimes web pages crash the browser. In B2G every web app and every browser tab runs in its own system process so that should the worst happen, it will only cause that one window/tab to crash. In fact, due to the memory constraints of the low-end smartphones B2G would initially target, sometimes the system will intentionally kill a background app or browser tab in order to conserve memory. The browser app needs to be informed when this happens and needs to be able to recover seamlessly so that in most cases the user doesn’t even realise a process was killed. Events were added to the Browser API for this purpose.


Crashed tab, version 1.0

Talking to Other Apps

Common use cases of a mobile browser are for the user to want to share a URL using another app like a social networking tool, or for another app to want to view a URL using the browser.

B2G implemented Web Activities for this purpose, to add a capability to the web for apps to interact with each other, but in an app-agnostic way. So for example the user can click on a share button in the browser app and B2G will fire a “share URL” Web Activity which can then be handled by any installed app which has registered to handle that type of Web Activity.


Share Web Activity, version 1.2

Working Offline

Despite the fact that B2G and Gaia are built on the web, it is a requirement that all of the built-in Gaia apps should be able to function offline, when an Internet connection is unavailable or patchy, so that the user can still make phone calls, take photos and listen to music etc.. At first we started to use AppCache for this purpose, which was the web’s first attempt at making web apps work offline. Unfortunately we soon ran into many of the common problems and limitations of that technology and found it didn’t fulfill all of our requirements.

In order to ship version 1.0 of B2G on time, we were forced to implement “packaged apps” to fulfill all of the offline and security requirements for built-in Gaia apps. Packaged apps solved our problems but they are not truly web apps because they don’t have a real URL on the Internet, and attempts to standardise them didn’t get much traction. Packaged apps were intended very much as a temporary solution and we are working hard at adding new capabilities like ServiceWorkers, standardised hosted packages and manifests to the web so that eventually proprietary packaged apps won’t be necessary for a full offline experience.


Offline, version 1.4

Spit and Polish

Finally we applied a good deal of spit and polish to the browser app UI to make it clean and fluid to use, making full use of hardware-accelerated CSS animations, and a sprinkling of Firefoxy interaction and visual design to make the youngest member of the Firefox browser family feel consistent with its brothers and sisters on other platforms.

Shipping 1.0

At an epic work week in Berlin in January 2013 hosted by Deutsche Telekom the whole B2G team, including engineers from multiple competing mobile networks and device manufacturers, got together with the common cause of shipping B2G 1.0, in time to demo at Mobile World Congress in Barcelona in February. The team sprinted towards this goal by fixing an incredible 200 bugs in one week.


Version 1.0 Team, Berlin Work Week, January 2013

In the last few minutes of the week Andreas Gal excitedly declared “Zarro Gaia Boogs”, signifying version 1.0 of Gaia was complete, with the rest of B2G to shortly follow over the weekend. Within around 18 months a dedicated team spanning multiple organisations had come together working entirely in the open to turn an empty GitHub repository into a fully functioning mobile operating system which would later ship on real devices as Firefox OS 1.0.1.


Zarro Gaia Boogs, January 2013


Browser app v1.0

So having attended Mobile World Congress 2012 with a prototype and a promise to deliver commercial devices into the market, we were able to return in 2013 having delivered on that promise by fully launching the “Firefox OS” brand with multiple devices on multiple mobile networks with a launch that really stole the show at the biggest mobile conference in the world. Firefox OS had arrived.


Mobile World Congress, Barcelona, February 2013


Firefox OS 1.1 quickly followed and by the time we started working on version 1.2 the project had grown significantly. We re-organised into autonomous agile teams focused on product areas, the browser app being one. That meant we now had a dedicated team with designers, engineers, a test engineer, a product manager and a project manager.


The browser team, London work week, July 2013

Firefox OS moved to a rapid release “train model” of development like Firefox, where a new version is delivered every 12 weeks. We quickly added new features and worked on improving performance to get the best out of the low end hardware we were shipping on in emerging markets.


Browser app v1.4


Version 1.0 of Firefox OS was very much about proving that we could build what already exists on other smartphones, but entirely using open web technologies. That included a browser app.

Once we’d proved that was possible and put real devices on shelves in the market it was time to figure out what would differentiate Firefox OS as a product going forward. We wanted to build something that doesn’t just imitate what’s already been done, but which plays to the unique strengths of the web to build something that’s true to Mozilla’s DNA, is the best way to experience the web, and is the platform that HTML5 deserves.

Below is a mockup I created right back towards the start of the project at the end of 2011, before we even had a UX team. I mentioned earlier that the Awesomebar is a core part of the Firefox experience in Firefox browsers. My proposal back then was to build a system-wide Awesomebar which could search the whole device, including your apps and their contents, and be accessible from anywhere in the OS.


Very early mockup of a system-wide Awesomebar, December 2011

At the time, this was considered a little too radical for version 1.0 and our focus really needed to be on innovating in the web technology needed to build a mobile OS, not necessarily the UX. We would instead take a more conservative approach to the user interface design and build a browser app a lot like the one we’d built for Android.

In practice that meant that we in fact built two browsers in Firefox OS. One was the browser app which managed the world of “web sites” and the other was the window manager in the system app which managed the world of “web apps” .

In reality on the web there isn’t so much of a distinction between web apps and web sites – each exists on a long continuum of user experience with a very blurry boundary in the middle.

In March 2013, with Firefox OS 1.0 out of the door, Josh Carpenter put me in touch with Gordon Brander, a member of the UX team who had been thinking along the same lines as me. In fact Gordon being as much of an engineer as he is a designer, had gone as far as to write a basic prototype in JavaScript.


Gordon’s Rocketbar Prototype, March 2013

Gordon and I started to meet weekly to discuss the concept he had by then codenamed “Rocketbar”, but it was a bit of a side project with a few interested people.

In April 2013 the UX team had a summit in London where they got together to discuss future directions for the user experience of Firefox OS. I was lucky enough to be invited along to not only observe but participate in this process, Josh being keen to maintain a close collaboration between Design and Engineering.

We brainstormed around what was unique about the experience of the web and how we might create a unique user experience which played to those strengths. A big focus was on “flow”, the way that we can meander through the web by following hyperlinks. The web isn’t a world of monolithic apps with clear boundaries between them, it is an experience of surfing from one web site to another, flowing through content.


Brainstorming session, London, April 2013

In the coming weeks the UX team would create some early designs for a concept (eventually codenamed “Haida”) which would blur the lines between web apps and web sites and create a unique user experience which flows like the web does. This would eventually include not only the “Rocketbar”, which would be accessible across the whole OS and seamlessly adapt to different types of web content, but also “sheets”, which would split single page web apps into multiple pages which you could swipe through with intuitive edge gestures. It would also eventually include a content model based around live apps which you can surf to, use, and then bookmark if you choose to, rather than monolithic apps which you have to install from a central app store before you can use them.

In June 2013 a small group of designers and engineers met in Paris to develop a throwaway prototype of Haida, to rapidly iterate on some of the more radical concepts and put them through user testing.


Haida Prototyping, Paris, June 2013


Josh and Gordon working in a highly co-ordinated fashion, Paris, June 2013


Wizards at work, Paris, June 2013

2.x and the Future

Fast forward to the present and the browser team has been merged into the “Systems Front End” team. The results of the Haida prototyping and user testing are slowly starting to make their way into the main Firefox OS product. It won’t happen all at once, but it will happen in small pieces as we iterate and learn.

In version 2.0 of Firefox OS the homescreen search feature from 1.x will be replaced with a new search experience developed in conjunction with a new homescreen, implemented by Kevin Grandon, which will lay the foundations for “Rocketbar”. In version 2.1 our intention is to completely merge the browser app into the system app so that browser tabs become “sheets” alongside apps in the task manager and the “Rocketbar” is accessible from anywhere in the OS. The Rocketbar will adapt to different types of web content and shrink down into the status bar when not in use. Edge gestures will allow you to swipe between web apps and browser windows and eventually apps will be able to spawn multiple sheets.


UI Mockups of Rocketbar in expanded and collapsed state, July 2014

In parallel we see the evolution of web standards around manifests, packages and webviews and ongoing discussions around what defines the scope of an “app”.

Version 1.x of Firefox OS was built with web technologies but still has quite a similar user experience to other mobile platforms when it comes to installing and using apps, and browsing the web. Going forward I think you can expect to see the DNA of the web come through into the user interface with a unified experience which breaks down the barriers between web apps and web sites, allowing you to freely flow between the two.

Firefox OS is an open source project developed completely in the open. If you’re interested in contributing to Gaia, take a look at the “Developing Gaia” page on MDN. If you’re interested in creating your own HTML5 app to run on Firefox OS take a look at the “App Center“.

by tola at August 07, 2014 02:41 PM

August 06, 2014

Chris Lamb

Strava Enhancement Suite update

I've been told I don't blog about my projects often enough, so here's a feature update on my Chrome Extension that adds various improvements to the fitness tracker.

All the features are optional and can be individually enabled in the options panel.

Repeated segments

This adds aggregate data (fastest, slowest, average, etc.) when segments are repeated within an activity. It's particularly useful for laps or—like this Everesting attempt—hill repeats:

Leaderboard default

Changes the default leaderboard away from "Overall" when viewing a segment effort. The most rewarding training often comes from comparing your own past performances rather than those of others, so viewing your own results by default can make more sense.

You can select any of Men, Women, I'm Following or My Results:

Hide feed entries

Hides various entry types in the activity feed that can get annoying. You currently have the option of hiding challenges, route creations, goals created or club memberships:

Variability Index

Calculates a Variability Index (VI) from the weighted average power and the average power, an indication of how "smooth" a ride was. Required a power meter. A VI of 1.0 would mean a ride was paced "perfectly", with very few surges of effort:

Infinite scroll

Automatically loads more dashboard entries when reaching the bottom, saving a tedious click on the "More" button:

Running TSS

Estimates a run's Training Stress Score (TSS) from its Grade Adjusted Pace distribution, a measure of that workout's duration and intensity relative to the athletes's capability, providing an insight into correct recovery time and overall training load over time:

Hide "find friends"

Hides social networking buttons, including invitations to invite or find further friends:

"Enter" posts comment

Immediately posts comment when pressing Enter/Return key in the edit box rather than adding a newline:

Compare running

Changes the default sport for the "Side by Side comparison" module to running when viewing athlete profiles:

Running cadence

Shows running cadence by default in the elevation profile:

Running heart rate

Shows running heart rate by default in elevation profile:

Estimated FTP

Selects "Show Estimated FTP" by default on the Power Curve page:

Standard Google map

Prefer the "Standard" Google map over the "Terrain" view:

Let me know if you have any comments, suggestions or if you have any other feedback. If you find this software useful, please consider donating via Paypal to support further development. You can also view the source and contribute directly on GitHub.

August 06, 2014 08:22 AM

July 22, 2014

MJ Ray

Three systems

There are three basic systems:

The first is slick and easy to use, but fiddly to set up correctly and if you want to do something that its makers don’t want you to, it’s rather difficult. If it breaks, then fixing it is also fiddly, if not impossible and requiring complete reinitialisation.

The second system is an older approach, tried and tested, but fell out of fashion with the rise of the first and very rarely comes preinstalled on new machines. Many recent installations can be switched to and from the first system at the flick of a switch if wanted. It needs a bit more thought to operate but not much and it’s still pretty obvious and intuitive. You can do all sorts of customisations and it’s usually safe to mix and match parts. It’s debatable whether it is more efficient than the first or not.

The third system is a similar approach to the other two, but simplified in some ways and all the ugly parts are hidden away inside neat packaging. These days you can maintain and customise it yourself without much more difficulty than the other systems, but the basic hardware still attracts a price premium. In theory, it’s less efficient than the other types, but in practice it’s easier to maintain so doesn’t lose much efficiency. Some support companies for the other types won’t touch it while others will only work with it.

So that’s the three types of bicycle gears: indexed, friction and hub. What did you think it was?

by mjr at July 22, 2014 03:59 AM

July 10, 2014

James Taylor


Is it annoying or not that everyone says SSL Certs and SSL when they really mean TLS?

Does anyone actually mean SSL? Have there been any accidents through people confusing the two?

July 10, 2014 02:09 PM

Cloud Computing Deployments … Revisited.

So its been a few years since I’ve posted, because its been so much hard work, and we’ve been pushing really hard on some projects which I just can’t talk about – annoyingly. Anyways, March 20th , 2011 I talked about Continual Integration and Continual Deployment and the Cloud and discussed two main methods – having what we now call ‘Gold Standards’ vs continually updating.

The interesting thing is that as we’ve grown as a company, and as we’ve become more ‘Enterprise’, we’ve brought in more systems administrators and begun to really separate the deployments from the development. The other thing is we have separated our services out into multiple vertical strands, which have different roles. This means we have slightly different processes for Banking or Payment based modules then we do from marketing modules. We’re able to segregate operational and content from personally identifiable information – PII having much higher regulation on who can (and auditing of who does) access.

Several other key things had to change: for instance, things like SSL keys of the servers shouldn’t be kept in the development repo. Now, of course not, I hear you yell, but its a very blurry line. For instance, should the Django configuration be kept in the repo? Well, yes, because that defines the modules and things like URLs. Should the nginx config be kept in the repo? Well, oh. if you keep *that* in then you would keep your SSL certs in…

So the answer becomes having lots of repo’s. One repo per application (django wise), and one repo per deployment containing configurations. And then you start looking at build tools to bring, for a particular server or cluster of servers up and running.

The process (for our more secure, audited services) is looking like a tool to bring an AMI up, get everything installed and configured, and then take a snapshot, and then a second tool that takes that AMI (and all the others needed) and builds the VPC inside of AWS. Its a step away from the continual deployment strategy, but it is mostly automated.

July 10, 2014 02:09 PM

June 28, 2014

Brett Parker (iDunno)

Sony Entertainment Networks Insanity

So, I have a SEN account (it's part of the PSN), I have 2 videos with SEN, I have a broken PS3 so I can no deactivate video (you can only do that from the console itself, yes, really)... and the response from SEN has been abysmal, specifically:

As we take the security of SEN accounts very seriously, we are unable to provide support on this matter by e-mail as we will need you to answer some security questions before we can investigate this further. We need you to phone us in order to verify your account details because we're not allowed to verify details via e-mail.

I mean, seriously, they're going to verify my details over the phone better than over e-mail how exactly? All the contact details are tied to my e-mail account, I have logged in to their control panel and renamed the broken PS3 to "Broken PS3", I have given them the serial number of the PS3, and yet they insist that I need to call them, because apparently they're fucking stupid. I'm damned glad that I only ever got 2 videos from SEN, both of which I own on DVD now anyways, this kind of idiotic tie in to a system is badly wrong.

So, you phone the number... and now you get stuck with hold music for ever... oh, yeah, great customer service here guys. I mean, seriously, WTF.

OK - 10 minutes on the phone, and still being told "One of our advisors will be with you shortly". I get the feeling that I'll just be writing off the 2 videos that I no longer have access to.

I'm damned glad that I didn't decide to buy more content from that - at least you can reset the games entitlement once every six months without jumping through all these hoops (you have to reactivate each console that you still want to use, but hey).

by Brett Parker ( at June 28, 2014 03:54 PM

June 27, 2014

MJ Ray

#coops14 sees last days of Downham Food Co-op


While  cooperatives fortnight is mostly a celebration of how well cooperatives are doing in the UK, this year is tinged with sadness for me because it sees Downham Food Coop stop trading.

This Friday and Saturday will be their last market stall, 9til 1 on the Town Square, aka Clock or Pump square.

As you can see, the downturn has hit the market hard and I guess being the last stall left outside the market square (see picture: it used to have neighbouring stalls!) was just too much. The coop cites shortage of volunteers and trading downturn as reasons for closure.

But if you’re near Downham today or tomorrow morning, please take advantage of this last chance to buy some great products in West Norfolk!

by mjr at June 27, 2014 10:14 AM

June 12, 2014

Paul Tansom

Beginning irc

After some discussion last night at PHP Hants about the fact that irc is a great facilitator of support / discussion, but largely ignored because there is rarely enough information for a new user to get going I decided it may be worth putting together a howto type post so here goes…

What is irc?

First of all, what on earth is it? I’m tempted to describe it as Twitter done right years before Twitter even existed, but I’m a geek and I’ve been using irc for years. It has a long heritage, but unlike the ubiquitous email it hasn’t made the transition into mainstream use. In terms of usage it has similarities to things like Twitter and Instant Messaging. Let’s take a quick look at this.

Twitter allows you to broadcast messages, they get published and anyone who is subscribed to your feed can read what you say. Everything is pretty instant, and if somebody is watching the screen at the right time they can respond straight away. Instant Messaging on the other hand, is more of a direct conversation with a single person, or sometimes a group of people, but it too is pretty instantaneous – assuming, of course, that there’s someone reading what you’ve said. Both of these techonologies are pretty familiar to many. If you go to the appropriate website you are given the opportunity to sign up and either use a web based client or download one.

It is much the same for irc in terms of usage, although conversations are grouped into channels which generally focus on a particular topic rather than being generally broadcast (Twitter) or more specifically directed (Instant Messaging). The downside is that in most cases you don’t get a web page with clear instructions of how to sign up, download a client and find where the best place is to join the conversation.

Getting started

There are two things you need to get going with irc, a client and somewhere to connect to. Let’s put that into a more familiar context.

The client is what you use to connect with; this can be an application – so as an example Outlook or Thunderbird would be a mail client, or IE, Firefox, Chrome or Safari are examples of clients for web pages – or it can be a web page that does the same thing – so if you go to and login you are using the web page as your Twitter client. Somewhere to connect to can be compared to a web address, or if you’ve got close enough to the configuration of your email to see the details, your mail server address.

Let’s start with the ‘somewhere to connect to‘ bit. Freenode is one of the most popular irc servers, so let’s take a look. First we’ll see what we can find out from their website,


There’s a lot of very daunting information there for somebody new to irc, so ignore most of it and follow the Webchat link on the left.


That’s all very well and good, but what do we put in there? I guess the screenshot above gives a clue, but if you actually visit the page the entry boxes will be blank. Well first off there’s the Nickname, this can be pretty much anything you like, no need to register it – stick to the basics of letters, numbers and some simple punctuation (if you want to), keep it short and so long as nobody else is already using it you should be fine; if it doesn’t work try another. Channels is the awkward one, how do you know what channels there are? If you’re lucky you’re looking into this because you’ve been told there’s a channel there and hopefully you’ve been given the channel name. For now let’s just use the PHP Hants channel, so that would be #phph in the Channels box. Now all you need to do is type in the captcha, ignore the tick boxes and click Connect and you are on the irc channel and ready to chat. Down the right you’ll see a list of who else is there, and in the main window there will be a bit of introductory information (e.g. topic for the channel) and depending on how busy it is anything from nothing to a fast scrolling screen of text.


If you’ve miss typed there’s a chance you’ll end up in a channel specially created for you because it didn’t exist; don’t worry, just quit and try again (I’ll explain that process shortly).

For now all you really need to worry about is typing in text an posting it, this is as simple as typing it into the entry box at the bottom of the page and pressing return. Be polite, be patient and you’ll be fine. There are plenty of commands that you can use to do things, but for now the only one you need to worry about is the one to leave, this is:


Type it in the entry box, press return and you’ve disconnected from the server. The next thing to look into is using a client program since this is far more flexible, but I’ll save that for another post.

by Paul Tansom at June 12, 2014 04:27 PM

May 06, 2014

Richard Lewis

Refocusing Ph.D

Actual progress on this Ph.D revision has been quite slow. My current efforts are on improving the focus of the thesis. One of the criticisms the examiners made (somewhat obliquely) was that it wasn&apost very clear exactly what my subject was: musicology? music information retrieval? computational musicology? And the reason for this was that I failed to make that clear to myself. It was only at the writing up stage, when I was trying to put together a coherent argument, that I decided to try and make it a story about music information retrieval (MIR). I tried to argue that MIR&aposs existing evaluation work (which was largely modelled on information retrieval evaluation from the text world) only took into account the music information needs of recreational users of MIR systems, and that there was very little in the way of studying the music information seeking behaviour of "serious" users. However, the examiners didn&apost even accept that information retrieval was an important problem for musicology, nevermind that there was work to be done in examining music information needs of music scholarship.

So I&aposm using this as an excuse to shift the focus away from MIR a little and towards something more like computational musicology and music informatics. I&aposm putting together a case study of a computational musicology toolkit called music21. Doing this allows me to focus in more detail on a smaller and more distinct community of users (rather than attempting to studying musicologists in general which was another problematic feature of the thesis), it makes it much clearer what kind of music research can be addressed using the technology (all of MIR is either far too diverse or far too generic, depending on how you want to spin it), and also allows me to work with the actually Purcell Plus project materials using the toolkit.

May 06, 2014 11:16 PM

March 27, 2014

Richard Lewis

Taking notes in Haskell

The other day we had a meeting at work with a former colleague (now at QMUL) to discuss general project progress. The topics covered included the somewhat complicated workflow that we&aposre using for doing optical music recognition (OMR) on early printed music sources. It includes mensural notation specific OMR software called Aruspix. Aruspix itself is fairly accurate in its output, but the reason why our workflow is non-trivial is that the sources we&aposre working with are partbooks; that is, each part (or voice) of a multi-part texture is written on its own part of the page, or even on a different page. This is very different to modern score notation in which each part is written in vertical alignment. In these sources, we don&apost even know where separate pieces begin and end, and they can actually begin in the middle of a line. The aim is to go from the double page scans ("openings") to distinct pieces with their complete and correctly aligned parts.

Anyway, our colleague from QMUL was very interested in this little part of the project and suggested that we spend the afternoon, after the style of good software engineering, formalising the workflow. So that&aposs what we did. During the course of the conversation diagrams were drawn on the whiteboard. However (and this was really the point of this post) I made notes in Haskell. It occurred to me a few minutes into the conversation that laying out some types and the operations over those types that comprise our workflow is pretty much exactly the kind of formal specification we needed.

Here&aposs what I typed:

module MusicalDocuments where

import Data.Maybe

-- A document comprises some number of openings (double page spreads)
data Document = Document [Opening]

-- An opening comprises one or two pages (usually two)
data Opening = Opening (Page, Maybe Page)

-- A page comprises multiple systems
data Page = Page [System]

-- Each part is the line for a particular voice
data Voice = Superius | Discantus | Tenor | Contratenor | Bassus

-- A part comprises a list of musical sybmols, but it may span mutliple systems
--(including partial systems)
data Part = Part [MusicalSymbol]

-- A piece comprises some number of sections
data Piece = Piece [Section]

-- A system is a collection of staves
data System = System [Staff]

-- A staff is a list of atomic graphical symbols
data Staff = Staff [Glyph]

-- A section is a collection of parts
data Section = Section [Part]

-- These are the atomic components, MusicalSymbols are semantic and Glyphs are
--syntactic (i.e. just image elements)
data MusicalSymbol = MusicalSymbol
data Glyph = Glyph

-- If this were real, Image would abstract over some kind of binary format
data Image = Image

-- One of the important properties we need in order to be able to construct pieces
-- from the scanned components is to be able to say when objects of the some of the
-- types are strictly contiguous, i.e. this staff immediately follows that staff
class Contiguous a where
  immediatelyFollows :: a -> a -> Bool
  immediatelyPrecedes :: a -> a -> Bool
  immediatelyPrecedes a b = b `immediatelyFollows` a

instance Contiguous Staff where
  immediatelyFollows :: Staff -> Staff -> Bool
  immediatelyFollows = undefined

-- Another interesting property of this data set is that there are a number of
-- duplicate scans of openings, but nothing in the metadata that indicates this,
-- so our workflow needs to recognise duplicates
instance Eq Opening where
  (==) :: Opening -> Opening -> Bool
  (==) a b = undefined

-- Maybe it would also be useful to have equality for staves too?
instance Eq Staff where
  (==) :: Staff -> Staff -> Bool
  (==) a b = undefined

-- The following functions actually represent the workflow

collate :: [Document]
collate = undefined

scan :: Document -> [Image]
scan = undefined

split :: Image -> Opening
split = undefined

paginate :: Opening -> [Page]
paginate = undefined

omr :: Page -> [System]
omr = undefined

segment :: System -> [Staff]
segment = undefined

tokenize :: Staff -> [Glyph]
tokenize = undefined

recogniseMusicalSymbol :: Glyph -> Maybe MusicalSymbol
recogniseMusicalSymbol = undefined

part :: [Glyph] -> Maybe Part
part gs =
  if null symbols then Nothing else Just $ Part symbols
  where symbols = mapMaybe recogniseMusicalSymbol gs

alignable :: Part -> Part -> Bool
alignable = undefined

piece :: [Part] -> Maybe Piece
piece = undefined

I then added the comments and implemented the part function later on. Looking at it now, I keep wondering whether the types of the functions really make sense; especially where a return type is a type that&aposs just a label for a list or pair.

I haven&apost written much Haskell code before, and given that I&aposve only implemented one function here, I still haven&apost written much Haskell code. But it seemed to be a nice way to formalise this procedure. Any criticisms (or function implementations!) welcome.

March 27, 2014 11:13 PM

February 22, 2014

Wayne Stallwood (DrJeep)

Outlook 2003, Cutting off Emails

I had a friend come to me with an interesting problem they were having in their office. Due to the Exchange server and Office licencing they have they are running Outlook 2003 on Windows 7 64bit Machines.

After Internet Explorer updates to IE11 it introduces a rather annoying bug into Outlook. Typed emails often get cut off mid sentence when you click Send ! So only part of the email gets sent !

What I think is happening is that Outlook is reverting to a previously autosaved copy before sending.

Removing the IE11 update would probably fix it but perhaps the easiest way is to disable the "Autosave unsent email" option in Outlook.

Navigate to:-
Tools, Options, E-Mail Options, Advanced E-Mail Options, and disable the "Autosave unsent" option.

February 22, 2014 08:43 AM

February 06, 2014

Adam Bower (quinophex)

I finally managed to beat my nemesis!

I purchased this book (Linked, by Barabasi) on the 24th of December 2002, I had managed to make 6 or 7 aborted attempts at reading it to completion where life had suddenly got busy and just took over. This meant that I put the book down and didn't pick it up again until things were less hectic some time later and I started again.

Anyhow, I finally beat the book a few nights ago, my comprehension of it was pretty low anyhow but at least it is done. Just shows I need to read lots more given how little went in.

comment count unavailable comments

February 06, 2014 10:40 PM

February 01, 2014

Adam Bower (quinophex)

Why buying a Mio Cyclo 305 HC cycling computer was actually a great idea.

I finally made it back out onto the bike today for the first time since September last year. I'd spent some time ill in October and November which meant I had to stop exercising and as a result I've gained loads of weight over the winter and it turns out also become very unfit which can be verified by looking at the Strava ride from today:

Anyhow, a nice thing about this ride is that I can record it on Strava and get this data about how unfit I have become, this is because last year I bought a Mio Cyclo 305 HC cycle computer from Halfords reduced to £144.50 (using a British Cycling discount). I was originally going to get a Garmin 500 but Amazon put the price up from £149.99 the day I was going to buy it to £199.99.

I knew when I got the Mio that it had a few issues surrounding usability and features but it was cheap enough at under £150 that I figured that even if I didn't get on with it I'd at least have a cadence sensor and heart rate monitor so I could just buy a Garmin 510 when they sorted out the firmware bugs with that and the price came down a bit which is still my longer term intention.

So it turns out a couple of weeks ago I plugged my Mio into a Windows VM when I was testing USB support and carried out a check for new firmware. I was rather surprised to see a new firmware update and new set of map data was available for download. So I installed it think I wasn't going to get any new features from it as Mio had released some new models but it turns out that the new firmware actually enables a single feature (amongst other things, they also tidied up the UI and sorted a few other bugs along with some other features) that makes the device massively more useful as it now also creates files in .fit format which can be uploaded directly to Strava.

This is massively useful for me as although the Mio always worked in Linux as the device is essentially just a USB mass storage device but you would have to do an intermediate step of having to use to convert the files from the Mio-centric GPX format to something Strava would recognise. Now I can just browse to the folder and upload the file directly which is very handy.

All in it turns out that buying a Mio which reading reviews and forums were full of doom and gloom means I can wait even longer before considering replacement with a garmin.

comment count unavailable comments

February 01, 2014 02:11 PM

January 04, 2014

Brett Parker (iDunno)

Wow, I do believe Fasthosts have outdone themselves...

So, got a beep this morning from our work monitoring system. One of our customers domain names is hosted with (which, as far as I can tell, is part of the Fasthosts franchise)... It appears that Fasthosts have managed to entirely break their DNS:

brettp@laptop:~$ host
;; connection timed out; no servers could be reached
brettp@laptop:~$ whois | grep -i "Name Server"
   Name Server: NS1.FASTHOSTS.NET.UK
   Name Server: NS2.FASTHOSTS.NET.UK
brettp@laptop:~$ whois | grep -A 2 "Name servers:"
    Name servers:
brettp@laptop:~$  host -t ns
;; connection timed out; no servers could be reached
brettp@laptop:~$ host -t ns
;; connection timed out; no servers could be reached

So, that's fasthosts core nameservers not responding, good start! They also provide, so lets have a look at that:

brettp@laptop:~$ whois | grep -A 3 "Name servers:"
    Name servers:
brettp@laptop:~$ host -t ns
;; connection timed out; no servers could be reached
brettp@laptop:~$ host -t ns
;; connection timed out; no servers could be reached
brettp@laptop:~$ host -t ns
;; connection timed out; no servers could be reached

So, erm, apparently that's all their DNS servers "Not entirely functioning correctly"! That's quite impressive!

by Brett Parker ( at January 04, 2014 10:24 AM

January 01, 2014

John Woodard

A year in Prog!

It's New Year's Day 2014 and I'm reflecting on the music of past year.

Album wise there were several okay...ish releases in the world of Progressive Rock. Steven Wilson's The Raven That Refused To Sing not the absolute masterpiece some have eulogised a solid effort though but it did contain some filler. Motorpsyco entertained with Still Life With Eggplant not as good as their previous album but again a solid effort. Magenta as ever didn't disappoint with The 27 Club, wishing Tina Booth a swift recovery from her ill health.

The Three stand out albums in no particular order for me were Edison's Children's Final Breath Before November which almost made it as album of the year and Big Big Train with English Electric Full Power which combined last years Part One and this years Part Two with some extra goodies to make the whole greater than the sum of the parts. Also Adrian Jones of Nine Stones Close fame pulled one out of the bag with his side Project Jet Black Sea which was very different and a challenging listen, hard going at first but surprisingly very good. This man is one superb guitarist especially if you like emotion wrung out of the instrument like David Gilmore or Steve Rothery.

The moniker of Album of the Year this year goes to Fish for the incredible Feast of Consequences. A real return to form and his best work since Raingods With Zippos. The packaging of the deluxe edition with a splendid book featuring the wonderful artwork of Mark Wilkinson was superb. A real treat with a very thought provoking suite about the first world war really hammed home the saying "Lest we forget". A fine piece that needs to be heard every November 11th.

Gig wise again Fish at the Junction in Cambridge was great. His voice may not be what it was in 1985 but he is the consummate performer, very at home on the stage. As a raconteur between songs he is as every bit as entertaining as he is singing songs themselves.

The March Marillion Convention in Port Zealand, Holland where they performed their masterpiece Brave was very special as every performance of incredible album is. The Marillion Conventions are always special but Brave made this one even more special than it would normally be.
Gig of the year goes again to Marillion at Aylesbury Friars in November. I had waited thirty years and forty odd shows to see them perform Garden Party segued into Market Square Heroes that glorious night it came to pass, I'm am now one very happy Progger or should that be Proggie? Nevermind Viva Progressive Rock!

by BigJohn (aka hexpek) ( at January 01, 2014 07:56 PM

December 01, 2013

Paul Tansom

Scratch in a network environment

I have been running a Code Club at my local Primary School for a while now, and thought it was about time I put details of a few tweaks I’ve made to the default Scratch install to make things easier. So here goes:

With the default install of Scratch (on Windows) projects are saved to the C: drive. For a network environment, with pupils work stored on a network drive so they always have access whichever machine they sit at, this isn’t exactly helpful. It also isn’t ideal that they can explore the C: drive in spite of profile restrictions (although it isn’t the end of the world as there is little they can do from Scratch).


After a bit of time with Google I found the answer, and since it didn’t immediately leap out at me when I was searching I thought I’d post it here (perhaps my Google Fu was weak that day). It is actually quite simple, especially for the average Code Club volunteer I should imagine; just edit the scratch.ini file. This is, as would be expected, located in:

C:\Program Files\Scratch\Scratch.ini

Initially it looks like this:


Pretty standard stuff, but unfortunately no comments to indicate what else you can do with it. As it happens you can add the following two lines (for example):


To get this:


They do exactly what is says on the tin. If you click on the Home button in a file dialogue box then you only get the drive(s) specified. You can also put a full path in if you want to put the home directory further down the directory structure.


The VisibleDrives option restricts what you can see if you click on the Computer button in a file dialogue box. If you want to allow more visible drives then separate them with a comma.


You can do the same with a Mac (for the home drive), just use the appropriate directory format (i.e. no drive letter and the opposite direction slash).

There is more that you can do, so take a look at the Scratch documentation here. For example if you use a * in the directory path it is replaced by the name of the currently logged on user.

Depending on your network environment it may be handy for your Code Club to put the extra resources on a shared network drive and open up an extra drive in the VisibleDrives. One I haven’t tried yet it is the proxy setting, which I hope will allow me to upload projects to the Scratch website. It goes something like:

ProxyServer=[server name or IP address]
ProxyPort=[port number]

by Paul Tansom at December 01, 2013 07:00 PM

February 22, 2013

Joe Button

Sampler plugin for the baremetal LV2 host

I threw together a simpler sampler plugin for kicks. Like the other plugins it sounds fairly underwhelming. Next challenge will probably be to try plugging in some real LV2 plugins.

February 22, 2013 11:22 PM

February 21, 2013

Joe Button

Baremetal MIDI machine now talks to hardware MIDI devices

The Baremetal MIDI file player was cool, but not quite as cool as a real instrument.

I wired up a MIDI In port along the lines of This one here, messed with the code a bit and voila (and potentially viola), I can play LV2 instrument plugins using a MIDI keyboard:

When I say "LV2 synth plugins", I should clarify that I'm only using the LV2 plugin C API, not the whole .ttl text file shebangle. I hope to get around to that at some point but it will be a while before you can directly plug LV2s into this and expect them to just work.

February 21, 2013 04:05 PM

January 16, 2013

John Woodard

LinuxMint 14 Add Printer Issue

 LinuxMint 14 Add Printer Issue


I wanted to print from my LinuxMint 14 (Cinnamon) PC via a shared Windows printer on my network. Problem is it isn’t found by the printers dialog in system settings. I thought I’d done all the normal things to get samba to play nice like rearranging the name resolve order in /etc/samba/smb.conf to a more sane bcast host lmhosts wins. Having host and wins, neither of which I’m using first in the order cocks things up some what. Every time I tried to search for the printer in the system setting dialog it told me “FirewallD is not running. Network printer detection needs services mdns, ipp, ipp-client and samba-client enabled on firewall.” So much scratching of the head there then, because as far as I can tell there ain’t no daemon by that name available!

It turns out thanks to /pseudomorph this has been a bug since LinuxMint12 (based on Ubuntu 11.10). It’s due to that particular daemon (Windows people daemon pretty much = service) being Fedora specific and should have no place in a Debian/Ubuntu based distribution. Bugs of this nature really should be ironed out sooner.

Anyway the simple fix is to use the more traditional approach using the older printer dialog which is accessed by inputting system-config-printer at the command line. Which works just fine so why the new (over a year old) printer config dialog that is inherently broken I ask myself.

The CUPS web interface also works apparently http://localhost:631/ in your favourite browser which should be there as long as CUPS is installed which it is in LinuxMint by default.

So come on Minty people get your bug squashing boots on and stamp on this one please.


Bug #871985 only affects Gnome3 so as long as its not affecting Unity that will be okay Canonical will it!

by BigJohn (aka hexpek) ( at January 16, 2013 12:39 AM

August 20, 2012

David Reynolds

On Music

Lately, (well I say lately, I think it’s been the same for a few years now) I have been finding that it is very rare that an album comes along that affects me in a way that music I heard 10 years ago seem to. That is not to say that I have not heard any music that I like in that time, it just doesn’t seem to mean as music that has been in my life for years. What I am trying to work out is if that is a reflection on the state of music, of how I experience music or just me.


Buying music was always quite an experience. I would spend weeks, months and sometimes longer saving up to buy some new music. Whether I knew exactly what I wanted or just wanted “something else by this artist” I would spend some time browsing the racks weighing up what was the best value for my money. In the days before the internet, if you wanted to research an artist’s back catalogue, you were generally out of luck unless you had access to books about the artists. This lead to the thrill of finding a hidden gem in the racks that you didn’t know existed or had only heard rumours about. The anticipation of listening to the new music would build even more because I would have to wait until I had travelleled home before I could listen to my new purchases.

Nowadays, with the dizzying amount of music constantly pumped into our ears through the internet, radio, advertising and the plethora of styles and genres, it is difficult to sift through and find artists and music that really speak to you. Luckily, there are websites available to catalogue releases by artists so you are able to do thorough research and even preview your music before you purchase it. Of course the distribution methods have changed massively too. No longer do I have to wait until I can make it to a brick and mortar store to hand over my cash. I can now not only buy physical musical releases on CD or Vinyl online and have it delivered to my door, I can also buy digital music through iTunes, Amazon or Bandcamp or even stream the music straight to my ears through services like Spotify or Rdio. Whilst these online sales avenues are great for artists to be able to sell directly to their fans, I feel that some of the magic has been removed from the purchasing of music for me.


Listening to the music used to be an even greater event than purchasing it. After having spent the time saving up for the purchase, then the time carefully choosing the music to buy and getting it home, I would then sit myself down and listen to the music. I would immerse myself totally in the music and only listen to it (I might read the liner notes if I hadn’t exhausted them on the way home). It is difficult to imagine doing one thing for 45+ minutes without the constant interruptions from smartphones, tablet computers, games consoles and televisions these days. I can’t rememeber the last time I listened to music on good speakers or headphones (generally I listen on crappy computers speakers or to compressed audio on my iPhone through crappy headphones) without reading Twitter, replying to emails or reading copiuous amounts of information about the artists on Wikipedia. This all serves to distract from the actual enjoyment of just listening to the music.


The actual act of writing this blog post has called into sharp focus the main reason why music doesn’t seem to affect me nowadays as much as it used to – because I don’t experience it in the same way. My life has changed, I have more resposibilities and less time to just listen which makes the convenience and speed of buying digital music online much more appealing. You would think that this ‘instant music’ should be instantly satisfying but for some reason it doesn’t seem to work that way.

What changed?

I wonder if I am the only one experiencing this? My tastes in music have definitely changed a lot over the last few years, but I still find it hard to find music that I want to listen to again and again. I’m hoping I’m not alone in this, alternatively I’m hoping someone might read this and recommend some awesome music to me and cure this weird musical apathy I appear to me suffering from.

August 20, 2012 03:33 PM

June 25, 2012

Elisabeth Fosbrooke-Brown (sfr)

Black redstarts

It's difficult to use the terrace for a couple of weeks, because the black redstart family is in their summer residence at the top of a column under the roof. The chicks grow very fast, and the parents have to feed them frequently; when anyone goes out on the terrace they stop the feeding process and click shrill warnings to the chicks to stay still. I worry that if we disturb them too often or for too long the chicks will starve.

Black redstarts are called rougequeue noir (black red-tail) in French, but here they are known as rossignol des murailles (nightingale of the outside walls). Pretty!

The camera needs replacing, so there are no photos of Musatelier's rossignols des murailles, but you can see what they look like on

by sunflowerinrain ( at June 25, 2012 08:02 AM

June 16, 2012

Elisabeth Fosbrooke-Brown (sfr)

Roundabout at Mirambeau

Roundabouts are taken seriously here in France. Not so much as traffic measures (though it has been known for people to be cautioned by the local gendarmes for not signalling when leaving a roundabout, and quite rightly too), but as places to ornament.

A couple of years ago the roundabout at the edge of  Mirambeau had a make-over which included an ironwork arch and a carrelet (fishing hut on stilts). Now it has a miniature vineyard as well, and roses and other plants for which this area is known.

Need a passenger to take photo!

by sunflowerinrain ( at June 16, 2012 12:06 PM

October 15, 2011

David Reynolds

Git Workflow

I’ve been using this for a while and had it recorded on a private on a private wiki. I was just tidying up my hosting account and thought I’d get rid of the wiki and store any useful info from it on my blog

Clone full subversion history into git repository (warning, may take a long time depending on how many commits you have in your Subversion repository).

$ git-svn clone -s local_dir

-s signifies trunk/ branches/ tags/ exist in the svn repo (standard repository setup)

Create branch for local changes and check it out

$ git checkout -b XXXX-description # where XXXX is a ticket number

Make my changes in the branch… Make my commits in the branch…

Change back to master branch

$ git checkout master

Merge branch as one commit to master

$ git merge --squash XXXX-description

Commit changes to master branch:

$ git commit -a

Push changes back to svn:

$ git svn dcommit

Resync local_changes to master:

$ git checkout XXXX-description
$ git rebase master

October 15, 2011 02:12 PM

September 04, 2006

Ashley Howes

Some new photos

Take a look at some new photos my father and I have taken. We are experimenting with our new digital SLR with a variety of lenses.

by Ashley ( at September 04, 2006 10:42 AM

August 30, 2006

Ashley Howes

A Collection of Comments

This is a bit of fun. A collection of comments found in code. This is from The Daily WTF.

by Ashley ( at August 30, 2006 01:13 AM