https://cygwin.com/cygwin/packages/summary/pngcrush.html
Cygwin Package Summary for pngcrush
package summarycygwinpngcrush
https://osxdaily.com/2013/08/15/pngcrush-mac-os-x/
Get pngcrush for Mac OS X with or without Xcode
Aug 21, 2013 - Get pngcrush for Mac OS X with or without Xcode
for mac os xgetpngcrushwithoutxcode
https://cygwin.com/pipermail/cygwin/2007-December/162715.html
[ANNOUNCEMENT] New package: pngcrush 1.6.4-1 -- Optimize PNG image files
new package1 6png imageannouncementpngcrush
https://www.jsdelivr.com/package/npm/pngcrush
pngcrush CDN by jsDelivr - A CDN for npm and GitHub
A free, fast, and reliable CDN for pngcrush. The pngcrush utility as a readable/writable stream
by jsdelivrpngcrushcdnnpmgithub