The Free Software Foundation has released GNU IceCat (a.k.a. Gnuzilla), the GNU version of the Mozilla Firefox web browser.
While the basic Mozilla Firefox source code is free software, and we thank them for their significant contributions to the community, some non-free files are distributed in the Firefox source tree, and Firefox can recommend non-free plugins. IceCat is entirely free.
In addition, GNU IceCat includes some privacy protection features:
Some sites refer to zero-size images on other hosts to keep track of cookies. When IceCat 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.)
Other sites rewrite the host name in links redirecting the user to another site, mainly to "spy" on clicks. When this behavior is detected, IceCat shows a message alerting the user.
