Proposed a few years ago by Vladimir Vukicevic and Stuart Parmenter, support for Animated Portable Network Graphics (APNG) images has finally landed on the trunk, Mozilla’s main development code.
PNG, is an image format developed in the mid-90s, mainly as an alternative to GIF files which were (and still are) widely used in millions of web sites after Unisys, the owner of the patent for this file format, started enforcing it. Besides being royalty free, PNG offers other advantages like a full pallette (GIF files can only use 256 colors at a time in a single file unless a really ugly hack is used), better compression and partial transparency which allows sharper images.
One final limitation of the PNG format was the lack of support for animated images, like GIF (GIF89a) do. MNG, an animated version of PNG was developed and even included in the Mozilla Application Suite until 2003, when it was removed after a very long discussion, because it was considered to be too heavy for a format with very limited support.
APNG, tackles the need in a different way and is implemented in a much smaller library. Browsers that don’t support APNGs will be able to display the first frame anyway, a big plus for the format.
There’s still several months before any Mozilla 1.9 code freeze, so hopefully, it will make it to Firefox 3 later this year. For users, it will mean fancier, smaller, open format based animated images. For ad haters, another rule for Adblock.