Community Hack

OWASP Sweden and FOSS-STHLM are doing a joint effort and we’re putting together Community Hack #2 on September 4-5 2010 here in Stockholm, Sweden.

We are looking for sponsors and facilities to use for this event, please get in touch!

The goal here is to gather a group of interested people. Everyone brings their own ideas of what to accomplish, communicate the intentions to the group and then work together during the weekend to try to reach the set goals. Suitable things, hacks, to work on during the weekend will of course be free and open code and not unlikely a fair amount of things will be security related.

The event is two full days, with some kind of social thing happening on the Saturday evening and with final presentations on Sunday afternoon.

Hopefully we can use each others’ competences and cross-feed between our different communities to get inputs, feedback and good spirit into the targeted projects.

This event is number 2 since the OWAPS guys already had Community Hack #1 back in January 2010, but at that time FOSS-STHLM wasn’t involved.

We gather all info about this event at


curl vs libcurl

In my mini-series of articles A vs B, the time is up for curl vs libcurl.

For me, the differences are so very clear and obvious but I get a fair stream of questions from users and random people that I thought it was about time to make an effort to once and for all make a page with the facts stated. A fixed home for curl vs libcurl knowledge.

So I did. And now I mentioned it to you. Enjoy! If you have additional content you think belong there or if you think anything is unclear or wrong, don’t hesitate to let me know!


Daniel’s currency exchange is no more

For quite a number of years I maintained a little web service to provide currency exchange rates in a handy format and in a way that was friendly for machines and other machine-exchangers. My personal favorite feature was the “easy conversion” helper that would provide a “easy to calculate in head” formula for back and forth between two currencies based on their current rates. Like “multiply by 5 and divide by 2” etc.

This service goes all the way back to 1997 when I started to work on getting exchange rates downloaded as a service to the IRC bot I ran in #amiga on efnet (even before the split when ircnet was created). Back then I was primarily working on the IRC bot named Dancer. 1997 I started the work on a tool to fetch rates. The tool would become curl and the web site to access the rates was initially hosted by the company Frontec for which I worked back then.One dollar bill

The URL changed a few more times but it has been available at for the last few years until a few weeks ago. Well, technically the URL still works but the service does not.

So a few weeks ago the primary site I’ve scraped for this info changed their format and I decided to not play cat and mouse anymore. I was already bending the rules by not reading their terms of service as I feared I wouldn’t be allowed to use their data like this. Also, I really don’t have any use for this service myself so I decided to do myself a service and stop wasting spare time on one of these projects that don’t give me enough personal satisfaction. I’m sure that if there is a demand for such a service I now closed down, there will be someone else out there ready to fire it up and serve users.

So long, and thanks for all the currency exchange fun.

Rockbox devcon is now

This weekend, in Ghent Belgium, the annual Rockbox developers conference “devcon” is taking place. Unfortunately I’m not there myself this year, but I can get a little sense of the atmosphere by following the live stream. Click the image to get to it. Do note that the stream will only be alive during this weekend June 5-6 2010.

Rockbox Devcon 2010 live stream

Here’s the team that was present at Devcon, picture from petur’s comment:


roffit lives!

Many moons ago I created a little tool I named roffit. It is just a tiny perl script that converts a man page written in the nroff format to good-looking HTML. I should perhaps also add that I didn’t find any decent alternatives then so I wrote up my own version. I’ve been using it since in projects such as curl, c-ares and libssh2 to produce web versions of the docs.

It has just done its job and I haven’t had any needs to fiddle with it. The project page lists it as last modified in 2004, even though I actually moved it to a sourceforge CVS repo back in 2007.

Just a few days ago, I got emailed and was notified that Debian has it included as a package in the distribution and someone was annoyed on some particular flaws.

This resulted in a bunch of bugs getting submitted to the Debian bug tracker, I started up the brand new roffit-devel mailing list to easier host roffit discussions and I switched over the CVS repo to a git one on github.

If you like seeing man pages turned into web pages, consider joining up and help us improve this thing!

Unexpected C64 reference

Yesterday at the OPTIMERA STHLM conference, Isac Lagerblad, really surprised me when he brought up an image of me and my fellow hackers in the C64 demo group named Horizon from back in the days of 1990. I’m the guy in the middle in the lower row.

You can see it happen at 02:35 into the part 4 clip, where you’ll go if you click on the image (Isac’s talk is in Swedish).

OPTIMERA STHLM sudden tribute to Daniel for cURL with C64 referenceThe original picture is a very old scan and isn’t a lot better:

I was honored and flattered by this unexpected “tribute”. Thanks Isac, it was really fun to see!

And before anyone asks: me and my brother Björn got our first Commodore 64 1985 and that is what got me into computers. I’ve not stopped enjoying them since then. We did a lot of demos, a few games and we had a great time and got similar minded friends all over the world.

My talk Optimera Sthlm

30 minutes is a tricky period to fill with contents when you do a talk, and yesterday I did my best at confusing/informing the audience at the OPTIMERA STHLM conference in transport layer performance. Where time is spent or lost today in TCP, what to think about to get things to behave faster, that RTT is not getting better even though brandwidth is growing really fast these days and a little about some future technologies like WebSockets, SPDY, SCTP and MPTCP.

Note: this talk is entirely in Swedish.

My slides for this is also viewable with like this: