GNUzilla and IceCat

 [GNU IceCat logo]

Introducing GNUzilla and IceCat

GNUzilla is the GNU version of the Mozilla suite, and GNU IceCat is the GNU version of the Firefox browser. Its main advantage is an ethical one: it is entirely free software. While the Firefox source code from the Mozilla project is free software, they distribute and recommend nonfree software as plug-ins and addons. Also their trademark license imposes requirements for the distribution of modified versions that make it inconvenient to exercise freedom 3.

Privacy protection features


Official releases of IceCat are available from, or any GNU mirror. Please use a mirror if possible. Besides the sources, binary releases for GNU/Linux (32 and 64 bit) are available.

IceCat is generated from Firefox with the scripts available at

Note that building binary packages for Windows and macOS currently requires nonfree software, so we no longer distribute binary releases for those platforms.

Free add-ons and plugins

We maintain a list of free addons.

GNUzilla runs its own plugin finder service at


You can find langpacks for IceCat in the official GNU FTP: in the "langpacks" directory for a given release.

These langpacks are generated automatically from the original Firefox ones, if you notice problems in your locale, please let us know at the <> mailing list.

Online help and documentation

Community driven manuals are available at

Mailing lists

The GNUzilla project uses a number of mailing lists, as follows:

To subscribe to the mailing lists, you may either use the mailman web interface (click on each list name and follow the instructions), or send an empty email with a Subject: header line of just subscribe to, replacing LISTNAME with any of the list names above (e.g. help-gnuzilla).

Found a bug? Have a suggestion? Please report it to the bug-gnuzilla list, trying to specify all the information that could be involved (platform, program version (the command icecat --version will report this), and build tools version if building from source code). Please report both the observed and the expected behaviors.

Getting involved

Development of IceCat, and GNU in general, is a volunteer effort, and you can contribute. For information, please read How to help GNU. If you'd like to get involved, please join our mailing lists and say hi!

The GNUzilla project is currently maintained by Ruben Rodriguez, Amin Bandali, Mike Gerwitz, and Mark H. Weaver. Please use the mailing lists for contact.

Origin of the name

The name “IceCat” was coined to show our relationship to the Mozilla Firefox browser. Ice isn't Fire and a Cat 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 nearly all of the work comes from the Mozilla foundation effort, so we want to give credit).

The gNewSense BurningDog browser and the Debian IceWeasel browser are similarly derived from Firefox, also with the intent of being free software. Technically, however, these projects are maintained entirely independently of IceCat. (Previously, this GNU browser project was also named IceWeasel, but that proved confusing.)

About GNU and the GNU Philosophy

The GNU Project was launched in 1984 to develop a complete Unix-like operating system which is free software—free as in freedom, not price. Its principal sponsor is the Free Software Foundation.

The free software philosophy is the root and motivation of the guidelines and goals of the whole free software movement, a worldwide community.

Please join us!

Please send FSF & GNU inquiries to <>. There are also other ways to contact the FSF.
Please send broken links and other corrections or suggestions to <>.

Copyright 2012, 2014 Free Software Foundation, Inc.

This page is licensed under a Creative Commons Attribution-NoDerivs 3.0 United States License.

We thank the Hitflip team for the IceCat logos.

Updated: $Date: 2019/11/09 07:28:51 $