A PHP program to compress, encrypt, and hide messages inside of PNG files.
Write up is here: http://www.joshianlindsay.com/index.php?id=126
Comments posted on that page will be answered.
Class source is well commented. The form.php file is the test fixture that the user interacts with, but it is not required. The class is stand-alone. The test fixture is mostly valuable as a usage example, as all of the class's major features are broken out into options.
Class and Form are both GPL-2, so be free.
If anyone is feeling generous, my bitcoin address is 17da1aqXEhdqMkbEq66nc2n5DeAnrnNbsK. Donations help me justify spending time on my computer to my wife. :-)
---J. Ian Lindsay