What about mng? It contains png and has layers and comments.
Yes, but still has the limitations of no-CMYK (Lab, ICC, etc.) colorspaces (among other things) out of the box...
Seems to be basically unmaintained.
PNG/MNG/JNG is fully supported and maintained by the libpng group, which is headed by Glenn Randers-Pehrson who is also one of the maintainers (along with myself) of ImageMagick and GraphicsMagick.
Leonard -- --------------------------------------------------------------------------- Leonard Rosenthol <mailto:leonardr@xxxxxxxxxxxxx> <http://www.lazerware.com>
