25 years of Dillo

Back in 1999, a group of developers lead by Jorge Arellano Cid forked the Gzilla/Armadillo code originally developed by Raph Levien, and began working on what is now known as the Dillo web browser.

Today, as of December of 2024, Dillo is 25 years old!

During this long journey, the project has seen a lot of changes and has stalled several times, but it managed to survive to this day. As a commemoration of this milestone I wanted to write a short history of the project.

Notice that Jorge had lead the project from 1999 until 2019, and as of today, we don't have more news about him. I hope he is okay and just decided to move on to other projects. Since then, I (Rodrigo) decided to resurrect the project and bring it back to life. I have no relationship with the previous developers, but I try to do my best to keep the original goals intact.

This document tries to tells the history as I have observed it through the pieces I was able to collect from the mailing list, the changelog and the git history.

GTK period (1999 - 2006)

When Dillo was forked, it was using GTK 1.0 as the UI library. The first releases were done in December of 1999 as recorded in the ChangeLog. At the time, this is how Gzilla 0.3.9 looked like:

During the initial development, Jorge first designed and wrote the naming convention for the function names (like prefixing them with a_ when they are public) or using 3 spaces for indentation, and began adjusting the code base to follow the same convention.

On March of 2000, the license was changed to the GPL with the permission of Raph Levien (the main developer of Gzilla/Armadillo).

The browser experimented a large rewrite with the idea to maintain several flows of communication following a signal driven approach. This work ended up in the publication Network programming internals of the Dillo Web browser by Jorge Arellano-Cid and H.H. Von Brand. This work would later derive in the Concomitant Control Chain (CCC), the mechanism that Dillo still uses today to track multiple connections and among its internal modules.

Sebastian Geerken began working on the code base at least since June of 2000. First submitting small patches and then moving to the rendering engine, of which he became the main architect. The rendering engine is one of the most important components of the browser, which essentially reads a tree of elements and determines the size and position of each element on the screen, like the words of paragraphs and images.

The support for HTML and CSS features started to grow during the coming years, specially for tables and text elements.

Shortly after GTK2 was released, the team was considering porting Dillo to it, but there were some concerns regarding the complexity and size of the new GTK version.

On October of 2003, Jorge asked the FLTK maintainer Michael Sweet if it would be feasible to port Dillo to FLTK, as it was considered to align better with the objectives of speed and stability:

We were following our plan to port dillo from GTK1 (currently used TK) to GTK2, when one of our list subscribers suggested considering FLTK because of shared philosophy backgrounds

The team decided to focus on FLTK 2 instead of GTK 2.0, as it was considered far more bloated and slow. Notice that at the time, FLTK 2 was not yet released, but is was planning to be released "soon".

On August 2004, Sebastian decided to make an interesting design decision, to make the Dillo widget toolkit independent. This way it was posible to continue the development of GTK1 and FLTK2 in parallel, among other benefits.

The most complex part is certainly Dw, since it is tightly bound to Gtk+. By all means, I want to prevent, that there exist different versions of Dw, with different features (e.g., when the development of the Gtk+ version continues, while the FLTK version is developed), which are hard to integrate.

For this reason (and others), I'm currently working on a redesign of Dw, which will make Dw toolkit independant. This is not the single goal of this redesign, it will also make some other features possible, e.g. a preview window, in which the whole page may be seen with reduced size, also, it will make reusage of Dw within graphical plugins possibel, and some more. (Actually, the idea for this design is already older, except the platform independency, but this was simple to add.)

During this period, the DPI mechanism (plugins) was improved and some functionality was moved to external programs that talk to the browser via the DPI protocol, like the downloads, bookmarks, FTP and also HTTPS. The version 0.8.3 released on October, 2004 had already HTTPS support. Here is how it looked like (still using GTK1):

During the following years, the development of the FLTK port was underway. The functionality that was provided by glib was implemented in a custom Dlib library so Dillo would not need to depend on glib anymore.

On February 2005, Jorge and Sebastian gave a talk at FOSDEM about the Dillo browser. Unfortunately, there is no recording of that talk. But shortly after, Jorge gave another talk at LSM in 2005, which was recorded, and was the first time the FLTK2 implementation was shown.

The last release that still used GTK1 was 0.8.6 on April, 2006. We will have to wait two years until the next release 2.0.0 was finally published with the port to FLTK2 completed.

FLTK 2 period (2005 - 2011)

The porting to FLTK2 was intended to make the browser smaller and provide other features like antialiasing. On April 2005, Jorge reported that the port to FLTK2 was making great progress.

Here are some good news with our current progress in porting dillo to FLTK. It has being going-on very fast and we have made great progress so far.

Here is how the browser looked like with FTLK2:

During this time however, the source code for the new FLTK2 port was not available in the CVS to the public. Instead, Jorge was focusing on rising funding to cover the project development from some interested companies.

On March 2006, Jorge reported that so far it was not being successful in attracting funding. The project faced a serious risk of stalling.

After mid 2006, there were no more releases of Dillo until 2008, and so far no success in getting more developers involved or funding for the project. The project was considered frozen or stalled and the FLTK2 port remained closed source.

On April 2007, Jorge reported that he had intentions to release the FLTK2 port as soon as Sebastian agreed.

In fact, I think it was more or less 6 months ago, after some emails with Andrew Tanenbaum, who finally helped me to see that it was a good time to release the code again. Since then, I've tried to contact Sebastian to agree on this.

This is an alpha release of the next generation of the Dillo web browser. The code underwent a major rewrite: significant parts of the codebase were ported to C++, and the rendering engine now uses the FLTK2 library instead of GTK1.

Please read the README inside dillo's tarball.

Developers willing to join the project and contribute are highly encouraged. Sebastian did an excellent work documenting the new dillo widget engine (just run doxygen inside DW tree).

This move started a lot of patches from other developers that were quickly integrated in the FLTK2 port. These contributions pushed Dillo towards an active state of development again.

On September of 2008, Jorge announced the support for tabs, which was included for the release. After a lot of bug fixing, the next version based on FLTK2 was ready and on October of 2008, Dillo 2.0.0 was finally released.

A year later, on July of 2009, Jorge announces that he is now a father, and his time for developing Dillo will (understandably) be affected.

I'm quite happy to let you know that yesterday 19 Aug [July], my first daughter Lisa was born!

Everything is OK, we're vey happy with this "release" :) and I just wanted to communicate it here, so you more or less know or understand my activities (or lack of) in the next days.

More features and bug fixes were added in the coming releases, until the last release of the 2.X series, the version 2.2.1 released on 2011. During this period, we don't observe more patches from Sebastian or emails in the mailing list.

Here is how Dillo was looking in the 2.2 version, very similar as how it looks today:

So, the team decided to switch to FLTK 1.3 as soon as it was released, and bump Dillo to the series 3.X.

FLTK 1.3 period (2011 - 2016)

On June 2011, with the FLTK 1.3 release done, the port of Dillo to FLTK 1.3 was underway. Only a few months later, the first 3.0.0 release using FLTK 1.3 was published.

On July of 2012, Sebastian presented a new hyphenation algorithm that implements the same mechanism used in TeX. This new implementation makes its way to the 3.0.3 release on April of 2013.

Several releases were made until the version 3.0.5 on June 2015.

During these last two years, we see a shift in the amount of commits introduced by Sebastian, which grow quite substantially.

Sadly, on October 2016, Sebastian passed away, leaving much of his work not included into a new release. Since then, the development quickly stalled until in 2019 Jorge sent his last email recorded by the mailing list, recommending a user to simply use the current version of the repository, rather than waiting for the 3.1 release:

> According to the info on
> https://hg.dillo.org/dillo/raw-file/default/ChangeLog, dillo-3.1 [not released yet].
>
> I will probably wait until they release it officially.

IMHO, you should get it. It's being stable for years.

--
Cheers
Jorge.-

After this moment, the project began to deteriorate. On 2022 the DNS domain of dillo.org was lost, causing the website, the mercurial repository, the mailing list and the email server to disappear.

The project quickly became abandoned, as there was no more developer activity anywhere. The dillo.org site now became a weird zombie copy of the once original website, but now plagued with SPAM in a Wordpress blog.

The resurrection (2024 - present)

On December of 2023, I began spending some time patching Dillo to make it build again. I tried to fix some simple bugs, and when I saw that the Atari forum had managed to port Dillo to Atari (!) based on my repo I though that it may be feasible to try to resurrect it. I commented it on Hacker News and it got surprised on the of interest it drew.

I first made a GitHub organization to hold the Git repositories and used the GitHub pages to make a new Dillo website. I tried to get a copy of all materials I could, and upload them to the new website and mailing list.

I tried to fix all the issues to finally make the 3.1.0 release, and after some months of work in my free time, I managed to release it on May of 2024. It caught the attention of several news sites and soon later it made its way to several Linux distributions.

As of today, 15 of December of 2024, I continue to maintain the project, and we are getting some new contributors which help with patches and discussion about the development. We are still far from having enough developers to cover all the issues, but we are slowly making some progress.

The last release of Dillo is 3.1.1, and this is what is looks like when loading the new Dillo website: