What file formats does Mozilla/Netscape
Mozilla supports any image format for icons that it recognises.
This includes .ico but also png, gif, jpeg and bmp. Although Netscape
supports many different file formats, we are not recommending users
to use anything other than .ico files at this time, since Mozilla/Netscape
is the only browser that supports other file favicon file formats.
Do I need to add special
html for my favicon to be seen?
Yes, you can use the same link tag as IE (the <link rel="shortcut
icon">) or you can also use <link rel="icon">
(optionally you can supply the mime type too: <link rel="icon"
type="image/png" href="...">). By default
Mozilla does not look for /favicon.ico instead relying on the link
tag. However a hidden preference will enable Mozilla to look for
favicon.ico. We recommend using the 'shortcut icon' link tag for
now (since IE does not support the icon tag yet).