This program converts APNG animations into animated GIF format. Wu64 quantization is used for true-color files. Transparency is handled either using a threshold, or composed over chosen background color. CLI version is OS-independent, GUI version is available for Windows.
Another converter: http://sourceforge.net/projects/gif2apng
Deconstruct APNG file into a sequence of PNG frames.
This program converts APNG file into a sequence of individual PNG frames. Command-line interface and GUI viersions.
Also, APNG Assembler can be found at http://sourceforge.net/projects/apngasm
This program converts GIF animations into animated PNG format. Usually it makes the files smaller. CLI version is OS-independent, GUI version is available for Windows.
Another converter: http://sourceforge.net/projects/apng2gif
Processor and realtime viewer for the program VXFlow (http://www.morgenthal.org/vxflow/), an numerical flow field simulator, written by Prof. Dr. Guido Morgenthal (http://www.uni-weimar.de/Bauing/MSK/?lang=en). This project uses the gloost framework.
CHAMP Animation Making Program, as its name suggests, aims to be a usable animation program primarily for GNU/Linux. It's currently being developed only by me (Thomas Clark), and is being written in C++. At the moment, CHAMP is not finished.