Originally proposed in 2004, Animated PNGs (APNG) were supposed to take over, providing higher quality animations, in exchange for large file sizes. However, in 2007, the PNG group completely reject to format and it never gained the popularity GIFs have now.
Before now, FireFox was one of the only major browsers to support the APNG format. We learned today from MacRumors that the iOS 8 update supports APNG in Safari. The post was later updated stating that OS X Yosemite also supports the file format.The Animated Portable Network Graphics (APNG) file format is a non-standard extension to the Portable Network Graphics (PNG) specification. It allows for animated PNG files that work similarly to animated GIF files, while supporting 24-bit images and 8-bit transparency not available for GIFs. It also retains backward compatibility with non-animated PNG files.