Clowder4DCH, a highly extensible active curation-based research data management platform. It contains three major extension points: preprocessing, processing and previewing. When new data is added to the system, preprocessing is off-loaded to extraction services for extracting appropriate data and metadata. The extraction services attempt to extract information and run preprocessing steps based on the type of the data, e.g., to create previews. This raw metadata is presented to the user via a web interface. Users can upload, download, search, visualize research datasets and explore information linked to data. Users can link and organise datasets in online collections following the provided workflows for creating semantically structured data repositories specialized for digital cultural heritage. It enables users to form an online collaboration environment to support research communities and activities, and disseminate results.