Is Plone available under a dual-license?
At this time, Plone is not available under licenses other than GPL, nor has it ever been. As of May 2009, the Plone Foundation has adopted a policy through which it may choose to relicense a limited number of Plone’s framework component modules under the modified BSD license in order to make it easier for developers to re-use these modules outside of Plone. This does not affect the overall licensing status of Plone. See our Framework Components Relicensing Policy for more information on this policy. As of May 2009, no packages have yet been released under an alternative license.