Firefox Logo History

Firefox logo inspired by seeing a Japanese brush painting of a fox.

One of the most visible enhancements is the new visual identity of Firefox and Thunderbird. It has often been argued that free software is typically designed only by programmers — rather than graphic designers or usability gurus — and that it frequently suffers from poor icon and GUI design and lacks a strong visual identity. The early Firebird and Phoenix releases of Firefox were considered to have had reasonable visual designs, but were not up to the same standard as many professionally released software packages.

In October 2003, professional interface designer, Steven Garrity, wrote an article covering everything he considered to be wrong with Mozilla's visual identity. The page received a great deal of attention (it was slashdotted). The majority of the criticisms levelled at the article were along the lines of "where's the patch?", an open source way of saying "if you don't like it, you can fix it yourself."Shortly afterwards, Garrity was invited by the Mozilla Foundation to head up the new visual identity team. The release of Firefox 0.8 in February 2004 saw the introduction of the new branding efforts, including new icons designed by Jon Hicks, who had previously worked on Camino. The logo was revised and updated later, fixing some flaws found when the logo was enlarged

The animal shown in the logo is a stylized fox, although "firefox" is considered to be a common name for the Red Panda. The panda, according to Hicks, "didn't really conjure up the right imagery", besides not being widely known. The logo was chosen for the purpose of making an impression, while not shouting out with overdone artwork. The logo had to stand out in the user's mind, be easy for others to remember and stand out while not causing too much distraction when among other icons. It was expected to be the final logo for the product.

The Firefox icon is a trademark used to designate the official Mozilla build of the Firefox software, and builds of official distribution partners.[3] Although the core software is open source, the artwork (along with the quality feedback agent and parts of the installer) is not freely licensed without official permission from the developers. For this reason, Debian and other software distributors who distribute patched or modified versions of Firefox do not use the icon.

Reference:
http://en.wikipedia.org/wiki/History_of_Mozilla_Firefox#Branding_and_visual_identity
http://www.hicksdesign.co.uk/journal/branding-firefox