Scientific research is becoming increasingly data centric, which requiresmore effort to manage, share, and publish data. NOMAD is a web-based platform thatprovides research data management (RDM) for materials-science data. In addition tocore RDM functionalities like uploading and sharing files, NOMAD automatically ex-tracts structured data from supported file formats, normalizes, and converts data fromthese formats. NOMAD provides an extendable framework for managing not just files,but structured machine-actionable harmonized and inter-operable data. This is the ba-sis for a faceted search with domain-specific filters, a comprehensive API, structureddata entry via customizable ELNs, integrated data-analysis and machine-learning tools.NOMAD is run as a free public service and can additionally be operated by researchinstitutes. Connecting NOMAD installations through the public services will allow afederated data infrastructure to share data between research institutes and further har-monize RDM within a large research domain such as materials science.