Lately, I’ve been working on a web app to learn more about JavaScript, jQuery and other technologies that web developers use. This app is available as a web app, on iPhones/iPads and on Android.

Markoshiki is a logic puzzle game, similar to Sudoku, Futoshiki, etc. The user needs to fill the numbers missing from a board, split in four quadrants, which already has some numbers in it.
The rules are simple:

  • Numbers grow in a clockwise direction following the arrows.
  • Consecutive numbers are in the same row or column as the previous number, but in different quadrants.
  • The numbers that are already in the board when you start the game cannot be modified.

Markoshiki with an empty board  Markoshiki with a partially filled board

For the next version I will focus on making the iOS and Android apps look more native, improve the flow of inserting notes (it’s a bit cumbersome now) and use better the available screen space (including support for landscape mode).

Please play online or install the apps.
If you have any feedback, please let me know at

Bye bye Bromium, hello Undo

In March 2015, I joined Bromium to work on a very cool security product. Unfortunately, my project was put on hold and I was not really interested in the new one, so I decided to leave.

In a couple of weeks, I will start working for Undo on their reversible debugger.
Imagine how cool it is to just wait to reproduce a bug and then step backwards to see what caused it instead of spending hours in a debugger hoping for a bug to happen! And all of this without affecting performance much!

Smart home?

I recently moved into a new home and I started to get it renovated. The first two steps were fixing the heating (I installed a evohome system and I’m very happy with it) and get some old roof Velux windows replaced as one wouldn’t open any more and another had some other problems.

Two of the windows are in the master bedroom close to the bed and the other one is in what will be the study, just on top of where a desk will be. Considering the unpredictable weather in England, I was worried that sudden rain would damage my bed and the stuff on the desk (probably a laptop).
Velux makes some automated roof windows, called Integra, that can close by themselves in case of rain, plus you can control them with a remote, you can set the blinds to open at a certain time of the day, etc.
The cost of the automated feature is small compared to the very expensive windows (roof windows are shockingly expensive compared to normal ones) and to the cost of replacing a laptop and mattress in case they get damaged by rain.

The windows seemed to work fine except from automated programs with a timer (for instance to wake you up by raising the blinds), but I assumed Velux could tell me how to fix this.
Today I came home from work and I discovered that all of the windows opened by themselves! And it was even raining!
Moreover, one of the windows damaged the insect net I got installed (mainly to keep my cat inside) by opening too much.
After this, one of the windows stopped responding to the remote control completely, see the picture below.

Velux Integra failure
The right window stopped working, the left one still works
(click for a bigger image)

Welcome to the glorious and shiny future of home automation!

Update: After spending some time resetting all the windows and controllers, I found out that probably the problem was due to a misbehaving remote controller that would just do things on its own (I watched while it was randomly and repeatedly clicking buttons on its own). The customer support at Velux was good and efficient and sent me a replacement controller.

Bye bye Collabora

Seven years ago, immediately after finishing my master’s degree, I visited Cambridge for an “interview” with Collabora. I was hired and, shortly afterwards, I moved to Cambridge.

It has been seven great years since then, even if there were some low points, like when Nokia cancelled some of their projects.
At Collabora I had the opportunity to learn a lot of new things and to work with a lot of incredibly competent and smart people. Despite this, after all this time, I felt like I wanted some little change, but not enough to start looking for another job and risk losing all the good things I had here at Collabora.

Recently, another company got in touch with me and offered me a job. The projects they work on are very interesting and the people there seem great (and, in many ways, similar to the people at Collabora). It was a difficult decision, but I decided to accept.

Today was my last day at Collabora. Thanks to everybody that I’ve met while working there! It was great!
Next week I will start working for Bromium!

(By the way, Collabora is hiring.)

WebKit on the new Raspberry Pi 2

Today the Raspberry Pi Foundation announced a new model of the Raspberry Pi!
While the new Raspberry Pi looks almost identical to the previous one, it’s much more powerful (and with four cores instead of one) and costs just $35.

Here at Collabora we have worked together with the Raspberry Pi Foundation on optimising WebKit for the first Raspberry Pi, achieving a good browsing experience (notwithstanding hardware limitations) with smooth 720 videos, good responsivity, etc.
Despite this work, a lot of web sites are just incredibly heavy and don’t run too well on the RPi1, so the extra CPU power is very useful. Just look at this video to see the difference in performances between the two Pis.

Comparison between the RPi1 and RPi2 (mp4 video file)

Our optimised WebKit-based web browser (i.e. GNOME Web, AKA Epiphany) is already available in Raspbian images, so you will get this out of the box.

A web browser for the Raspberry Pi

As I previously mentioned, Collabora has been working with the Raspberry Pi Foundation on various projects including a web browser optimised for the Raspberry Pi.
Since the first beta release we have made huge improvements; now the browser is more responsive, it’s faster, and videos work much better (the first beta could play 640×360 videos at 0.5fps, now we can play 25fps 1280×720 videos smoothly). Some web sites are still a bit slow (if they are heavy on the JavaScript side), but there’s not much we can do for web sites that, even on my laptop with an Intel Core i7, use 100% of one of the cores for more than ten seconds!

The browser is based on Gnome Web (Epiphany) using WebKit 1 (i.e. the non-multi-process version of WebKit).

Our main achievements are:

  • More responsive UI and scrolling, even under heavy load (like when loading a page)
  • Progressive tiled rendering for smoother scrolling (as mobile browsers do)
  • Startup is three times faster
  • Avoid useless image format conversions
  • Better YouTube support, including on-demand load of embedded YouTube videos to make page load much faster
  • Hardware decoding of videos (through gst-omx)
  • Hardware scaling of videos (again, through gst-omx)
  • Reduction of the number of memory copies to play videos
  • Faster fullscreen playback using dispmanx directly (a bit buggy at the moment, we are working on it)
  • Memory and CPU friendly tab management
  • JavaScript JIT fixes for ARMv6
  • Disk image cache (decoded images are kept in memory mapped files in a cache, saving CPU)
  • Memory pressure handler support

The Raspberry Pi web browser (mp4 video file)

To install the browser, just update your Raspbian and install the “epiphany-browser” package:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install epiphany-browser

Thanks to all the people at Collabora that, at some point or another, helped on this project: Julien Isorce, Emanuele Aina, ChangSeok Oh, Tomeu Vizoso, Pekka Paalanen, André Moreira Magalhaes, Derek Foreman, Gustavo Noronha, Danilo Cesar, Emilio Pozuelo Monfort and Jonny Lamb (I hope I haven’t forgotten anybody!).
Also thanks to the Raspberry Pi Foundation, and in particular to Eben Upton, for their commitment to making browsing on the Pi better, and to Ben Avison for his work on optimising pixman and libav for ARMv6.

Update: people have reported a few bugs since the release, in particular a problem with Raspbian configured to use 24-bit or 32-bit mode for graphics. We should be able to fix this in a week or so.
Another problem is that Vimeo videos stopped working. This seems to be due to a change made by Vimeo that broke playback also on other browsers and on Android.

Maynard: a Wayland desktop shell for the Raspberry Pi

In the last year or so, Collabora has been working with the Raspberry Pi Foundation on a web browser and on Wayland. See Daniel’s and Pekka’s blog posts about their Wayland work.

To make Wayland on the Raspberry Pi actually usable, we needed a shell, but lightweight desktop environments (like LXDE) don’t support Wayland and normal desktops (like Gnome and KDE) are just too heavy.
This meant we ended up writing our own shell based on Tiago Vignatti’s gtk-shell, so Maynard was born!

Maynard running on my laptop (webm video file)

Maynard running on a Pi (mp4 video file)

Maynard is far from complete, but it’s already starting to take shape nicely. Its goals are to be functional, light and pretty, so it will never see some of the features one might expect from Gnome or KDE for instance.

The main current limitations are:

  • No XWayland support, so non-Wayland applications cannot run (issue #1).
  • GTK applications take too long to start (issue #2).
  • Active apps are not shown in the panel (issue #3).
  • No configurability (issue #7). I hope you like the background from kdewallpapers we use as you cannot change it for now ;)

Interested in the project? Follow these links:

Previous Articles

Empathy chat accounts and GOA

New versions of Message Notifier and Boss mode

What’s happening in Italy?

Welcome to my blog

meI'm an Italian software engineer living in Cambridge (UK). Here I work for Collabora on open source projects like GNOME and Telepathy.
I have a skeleton in the cupboard: Opera is my favourite web browser.