This is the personal web page of Mats Sjöberg. I work as a computer science researcher. I care about social and economic justice. I like reading, walking and programming. I live in Espoo, Finland together with my wife and son.

Contact details

The best way to contact me is via email: My PGP key is 8A9F94D8.

I’m also using Signal for instant messaging and Mastodon for social networking:

My professional contact details can be found on my researcher web page.

This web page also hosts my blog. I haven’t updated it since 2014, I’m just keeping it for archival purposes.


Here are links to some free and open source software that I have created. If you find any bugs or have any questions about them, you can e-mail me or use the bug trackers associated with each project.


Pumpa is a simple client written in C++ and Qt. Pumpa was mentioned on LWN: “Searching for a client”.

Pumpa’s documentation, source code and bug tracker are hosted on branchable.


A simple but addictive game in the Match-3 genre for the Nokia N9 (MeeGo Harmattan) and newer Nokia Symbian phones (Anna and Belle operating systems). The game got over 100,000 downloads in the Nokia Ovi Store!

Since the Nokia Ovi Store has been discontinued, you can get Heebo for Symbian phones in the Opera Mobile Store.

Kimmo Lindholm has ported Heebo to the Jolla phone, and it has been highly popular also there.

Heebo support page for N9 and Symbian.


A very simple client in Qt. It also includes a client for Nokia N9/N950, which is usable, but perhaps not quite ready for general adoption.

In November 2014 Stig Atle Steffensen took over as maintainer of the project.

Download for Nokia N9/N950: yaics_0.1.1_armel.deb (updated December 26, 2013).

Blog post about Harmattan Nokia N9/N950 client.


Very simple command line podcast client in Python, that I made for my personal use. I put it here in case someone else finds it useful.

The most recent code can be fetched from the git repository.

JavaScript toys

ColourSOM is a simple HTML5 canvas + JavaScript application that demonstrates the Self-Organising Map algorithm by using random colours.

JSMandel just draws the Mandelbrot set, no zooming yet…

Miscellaneous links

Old fashioned list of links to stuff.

Web pages of friends and relatives

Niklas Gustafsson | Johan Paul | Anders Gustafsson
Åse och Micke | Kjell-Mikael Källman

Organisations I’m a member of

Left Alliance
Amnesty | ATTAC | Skepsis ry
Electronic Frontier Finland ry | FSF Europe
ACM | Pattern Recognition Society of Finland / IAPR