[4] IceCat is released as a part of GNUzilla, GNU's rebranding of a code base that used to be the Mozilla Application Suite.

The GNU Project attempts to keep IceCat in synchronization with upstream development of Firefox (long-term support versions) while removing all trademarked artwork and non-free add-ons.

[5] Unless distributions use the binary files supplied by Mozilla, fall within the stated guidelines, or else have special permission, they must compile the Firefox source with a compile-time option that creates binaries without the official branding of Firefox and related artwork, using either the included free artwork or an alternative specified by the person doing the build.

[9] In August 2005,[10] the GNUzilla project adopted the GNU IceWeasel name for a rebranded distribution of Firefox that made no references to nonfree plugins.

[10] The term "ice weasel" appeared earlier in a line which cartoonist Matt Groening fictionally attributed to Friedrich Nietzsche: "Love is a snowmobile racing across the tundra and then suddenly it flips over, pinning you underneath.

[12] However, because the artwork in Firefox had a proprietary copyright license at the time, which was not compatible with the Debian Free Software Guidelines, the substituted logo had to remain.

[16] Some Linux Distributions offer binary and source packages through their repositories, such as Trisquel,[17] Parabola GNU/Linux-libre[18] and Fedora.