It can read and write files from the Mac OS X icns format, as well as
read from Mac OS resource files and macbinary encoded Mac OS resource
forks. As of release 0.5.9, it can fully read and write any 128x128 and
all smaller 32-bit icons, and read support for 8-bit, 4-bit, and 1-bit
icons. If linked against Jasper, it also has full support for 256x256
and 512x512 32-bit icons with masks as alpha channels.

The package contains icns2png, png2icns and icontainer2icns.