Mozilla’s Justin Dolske, has released APNG Editor, a powerful Firefox extension to compose animated PNG files, one of the new features Firefox 3 will bring later this year.

As announced before, APNGs are a more powerful and completely patent free option for producing and delivering small animations on the web.

I gave it a try and made the lame example you see to the right (or most likely not, since it only works in Gran Paradiso Alpha 2 and later).

It proved to be very easy to use: create as many frames as you need, add an image to each frame, set a time to be displayed each and if you want the animation to loop once, twice or forever.

Another great feature, is that you can  set the animation to start on the second frame instead of the first one. Why would someone could possibly want to do this? Because browsers that don’t support APNGs will show the first frame only, but it could not fit with the rest of the animation, so you can exclude it at all as provided by the specification.

A lot remains to be done though like an option to load and edit a APNG but it’s planned. Then there’s an option to load a JavaScript file and some frame compositing options I don’t get but must be the key to the most sophisticated options APNGs offer.

For more interesting examples, grab a nightly and see Justin Dolske’s demo page.  Try APNG Editor here.