The basis of metadata is the json-based RO-Crate standard. This means that every metadata object must adhere to the schema.org standard. These standards enable more flexiblity on nearly every point compared to version 2.

This for example allows for:

• One metadata definition collecting multiple data entries
• One metadata definition collection other metadata definitions
• Distributed linked metadata
• inclusion of descriptions for non-aruna metadata links

Collaborative editing of metadata is handled by CRDTs, allow for flexible asynchronous merging of changing actions. Every change results in a new version that gets collected in a version history. Each change not only includes the resulting action, but also the user that triggered the change, the node that executed the change and the realm where the action took place in. Because metadata can now contain metadata that is located at other nodes or even realms, the distribution of metadata and data becomes easier than before. This not only allows for much higher scaliblity than version 2, allowing for example the integration of massive databases inside the p2p-aruna system, but also giving researchers the possibility to store data on a resilient federated system.