ODRL

Short for ODRights Language, a standard for expressing content rights metadata. ODRL is a digital rights data model with an XML-based specification language to be used in content distribution services, including the expression of terms and conditions over any content including permissions, constraints, obligations, conditions, and offers and agreements with rightsholders.

ODRL is a competing technology with XrML. ODRL has no licensing requirements and is meant in the spirit of open source.