National Libraries and a Museum open up their data using CC0 - Creative Commons

"CC0 has been getting lots of love in the last couple months in the realm of data, specifically GLAM data (GLAM as in Galleries, Libraries, Archives, Museums). The national libraries of Spain and Germany have released their bibliographic data using the CC0 public domain dedication tool. For those of you who don’t know what that means, it means that the libraries have waived all copyrights to the extent possible in their jurisdictions, placing the data effectively into the public domain. What’s more, the data is available as linked open data, which means that the data sets are available as RDF (Resource Description Framework) on the web, enabling the data to be linked with other data from different sources...."