Submitted by Jehan
While formats as WebP still have quite limited support in browsers, I can see APNG has much broader support (all but microsoft browsers according to Wikipedia). It would be definitely interesting to have support.
There exists a plug-in already in GPLv3 for 2.8: http://registry.gimp.org/node/24394 https://sourceforge.net/p/gimp-apng/code/ci/master/tree/
It may be worth salvaging it and looking for support in 2.10. Note that it looks like APNG is an extension of PNG, and therefore it will likely have to be in the PNG plug-in as an animation option.
Version: git master