Commercial License
$20
OneFileCMS is free* and open source, protected by a Creative Commons "Attribution Non-Commercial ShareAlike" License. You may remix, tweak, and build upon this software non-commercially, as long as you credit "http://onefilecms.com/" and license any new creations under identical terms. All new work based on yours will carry the same license, so any derivatives will also be non-commercial in nature.
*OneFileCMS is free for personal or non-commercial websites. To receive an exception to use this software commercially, please purchase a $20 commercial license. The aforementioned attribution and derivation terms will still apply. Commercial licenses are good per domain or entity and do not need to be renewed when installing updates. They may not be used cross-domain or cross-client. (An unlimited commercial license is available for $100.)
Lastly, this software is provided "as is," without warranty of any kind. In no event shall its author or the authors of its revisions be liable for any claim, damages, or other liability.
For good. Not evil.