From EPSIplatform Blog:
The Swiss National Library has started making available all of its metadata from the ‘Helveticat’ catalogue as open data. This as part of their general open data strategy. The data is being made available through API’s to everyone. The data is licensed under Creative Commons 0, allowing everyone to re-use the data for any purpose and without crediting the source.
The post also mentions that the library has plans to provide access to open data from their other databases.