George Peter Staplin Sep 24, 2007 - Animng is a file format I created for animated PNG graphics. It's a portable binary format, with a freely available library written in C, as well as a separate Tcl extension.
The file format allows for a variable delay between frames, as well as an x,y offset for frames (not yet used in the demos or mkanimng). It requires libpng.
The code is available from here under a 3 clause BSD license: http://megapkg.googlecode.com/svn/trunk/csrc/animng/ http://megapkg.googlecode.com/svn/trunk/csrc/include/animng.h http://megapkg.googlecode.com/svn/trunk/csrc/include/animng_prototypes.h
A tool for making animng binary files is available here: http://megapkg.googlecode.com/svn/trunk/csrc/mkanimng.c
An extension for Tcl using megaimage is written about on the animngext page.