LibPNG 1.6.18 is available for OS/2 and eComStation
Hobbes: http://hobbes.nmsu.edu/h-search.php?key=libpng
"libpng is the official PNG reference library. It supports almost all PNG features, is extensible, and has been extensively tested for over 20 years."
LibPNG URL: http://www.libpng.org/
Port by: KO Myung-Hun