On Repositories - Cornerstones of Open Science - and how OSCARS and the Science Clusters contribute to them

In the context of Open Science, repositories are digital platforms for the short and/or long-term storage, management, and/or sharing of research data, publications and other scholarly materials. They serve multiple purposes, such as long-term preservation, computation, archiving, and dissemination. They support FAIR principles by providing metadata, persistent identifiers, and access controls, which are crucial to make research findable, accessible, and reusable. Trusted repositories also promote transparency, reproducibility, and societal impact, as shown during the COVID-19 pandemic and challenges around data sharing and data mobilisation. The five Science Clusters - ENVRI, ESCAPE, LS-RI, PaNOSC, and SSHOC - have each developed complementary repository strategies, from federated data lakes, to domain-specific workflows and metadata standards. Through OSCARS, these efforts are being consolidated into interoperable, FAIR-aligned infrastructures that strengthen cross-disciplinary collaboration in the European Open Science Cloud (EOSC). OSCARS also encourages repository development, training, and certification to increase data sharing and Open Sciences, while ensuring that its funded projects deposit their outputs in trusted open access repositories.