Progressive License
Progressive License is a plugin that gives authors an opportunity to put Creative Commons or Custom Licenses on their content, with the additional benefit of being able to change the license that is applied as the content ages. This plugin provides a robust solution for managing the varying licensing needs of content, whether it be changing licenses over time or applying different licenses to different content.
Progressive License ships with seven Creative Commons licenses included out of the box, but also provides an interface to add additional licenses as needed.
Development of this plugin was sponsored by RedMonk, who deserves accolades for supporting the community by deciding to have us build this for open source use rather than as a custom plugin.