In line with the maxim “release early, release often”, here is the initial public viewing of my work on pngtools. At the moment, the only command that is implemented is pnginfo, which is pretty much there (apart from the command line options, which are rarely used).
I would welcome comments on the code, which can be sent to mikal@stillhq.com. The code is (c) Michael Still 2001, and is released under the GNU GPL version 2.
A historical note from November 2020: this code is quite old, but still actively used. I have therefore converted the old subversion repository to git and it is hosted at https://github.com/mikalstill/pngtools. I will monitor there for issues and patches and try my best to remember what I was thinking 20 years ago…