pHash is open source software released under the GNU General Public License (GPL) version 3. This means that if you use pHash in your application, it must also be released under the GPLv3. If you wish to distribute a commercial application without including source code, you must obtain a commercial license.
pHash is copyright 2008-2010 Aetilius, Inc.
pHash is a registered trademark of Evan Klinger.
If you are using pHash and would like to be listed, please let us know.