The Royal Library (National Library of Denmark and Copenhagen University Library) recently released a new Hydra application named Chronos.
Details of the project can be found here: http://www.kb.dk/en/nb/afdelinger/db/index.html
The project spanned a little over two years during which the bulk of the work was in establishing policies for long term digital preservation and then setting a strategic plan based on the policies.
The work then segued into the cost models to support the newly developed policies and strategic plan. Using a shared set of principle and guidelines from Collaboration to Clarify the Cost of Curation (http://www.4cproject.eu/), they developed a sustainable cost model for long term preservation of their digital assets.
Once they had policies, strategies and costs established, they moved their work into a more detailed level and focused on the metadata requirements for preservation. The focus was on event data to be stored in PREMIS and structure data to be stored in METS. This led to much more detailed discussions related to the discovery of the digital assets for public discovery as well as metadata required for creating internal reports for performing tasks related to digital preservation.
Once this work was complete, they moved into the process of specifications for the system. They selected Hydra as the best approach for digitally preserving millions of documents. The planning process started in June 2014 and continued through the end of October 2014. This past December work begun on the new system and the week of March 16, 2015 they will release videos and additional information to the Hydra community.