Gnuzilla and IceWeasel

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Introducing Gnuzilla and IceWeasel

Gnuzilla is the GNU version of the Mozilla suite, and IceWeasel is the GNU version of the Firefox browser. Its main advantage is an ethical one: it is entirely free software. While the source code from the Mozilla project is free software, the binaries that they release include additional non-free software. Also, they distribute non-free software as plug-ins. (IceWeasel does keep the triple licensing used by Firefox to facilitate the reuse of code.)

IceWeasel also includes some privacy protection features:

  1. Some sites refer to zero-size images on other hosts to keep track of cookies. When IceWeasel detects this mechanism it blocks cookies from the site hosting the zero-length image file. (It is possible to re-enable such a site by removing it from the blocked hosts list.)
  2. Other sites rewrite the host name in links redirecting the user to another site, mainly to "spy" on clicks. When this behavior is detected, IceWeasel shows a message alerting the user.
To see these new features in action, some test pages are available. Fredrik Hubbe's web site can be used test plugins.

IceWeasel name origins

The original name "IceWeasel" was coined by Nathanael Nerode in 2004. Ice isn't Fire and a Weasel isn't a Fox, so it is clearly a different package (we don't want Mozilla blamed for our mistakes, nor cause confusion with their trademarks), but is equally clearly intimately related (of course the vast bulk of the work comes from the Mozilla foundation efforts, so we want to give credit).


We currently have a test release available from

The changed files for the development sources are available through the Gnuzilla savannah project. You can check them out via anonymous CVS:

cvs co gnuzilla
The complete exploded source tree is also available.

Mailing lists

Gnuzilla and IceWeasel discussion takes place on the mailing list Feel free to subscribe or browse the archives.

To subscribe to the Gnuzilla mailing list, either use the mailman web interface or send an empty mail with a Subject: header line of just "subscribe" to the relevant -request list. In this case, send mail to with no body and a Subject: header line of just "subscribe".

Found a bug? Please report it to the mailing list, trying to specify all the information that could be involved (platform, program version (the command iceweasel --version will report this), and build tools version if building from source code). Please explain the bug by comparing the behavior you expected to the behavior you observed.

Free plugin finder configuration

Gnuzilla runs its own plugin finder service at To specify this at runtime, access the url about:config in your browser, find the pfs.datasource.url attribute, and change the host to Also change the protocol from https to http, if necessary. Be careful not to change the rest of the string (after the first single /).

Help wanted

Development of Gnuzilla and IceWeasel is a volunteer effort, and additional contributors are welcome: developers, testers, documentation writers, or any other area. Please write the mailing list for the project. For information about contributing to the GNU Project in general, please read How to help GNU.

It would be particularly helpful to test Iceweasel with GNU Gnash.

The primary maintainer of Gnuzilla and IceWeasel is Giuseppe Scrivano.