Here, we describe the RISIS-SMS metadata system, developed to support the use of heterogeneous datasets in the field of Science, Technology and Innovation Studies (STIS). These data are partly within the RISIS infrastructure, but often elsewhere. The system has three aims: (i) to help researchers to search for and understand data that will help to answer specific research questions, without having to access or download the data. As datasets often have restricted access, browsing metadata is a key feature of the system: researchers need help identifying the relevant data from different sources for their research, and for which data it is worthwhile asking for access; (ii) to support the enrichment of data By linking the metadata system to the Linked Open Data environment (LOD); (iii) to facilitate application-driven data integration