Assemble APNG animations from PNG image sequences.
This is the command line tool to create APNG files from
individual PNG files.

The Animated Portable Network Graphics (APNG) file format is an
extension to the Portable Network Graphics (PNG) specification. It
allows for animated PNG files that work similarly to animated GIF
files, while retaining backward compatibility with non-animated PNG
files and adding support for 8-bit transparency and 24-bit images.
