Open Data Registry provides Internet infrastructure and web services for the Green Economy. Just as financial accounting provides the foundation for the traditional economy, so will green accounting be the basis of the Green Economy. This means keeping track of all inputs and outputs related to industrial activity and consumption, particularly those that take resources from the natural environment or emit harmful substances into the environment. Keeping track of this generates a lot of data. Furthermore, the data is distributed in nature across geography, company, and business functional boundaries. This presents unique challenges that are best met by the Internet, in particular the powerful Semantic Web technologies that have been developed in recent years.