The ELIXIR Recommended Interoperability Resources (RIRs) are tools and registries that have been selected by a panel of external reviewers. These resources build a network of foundational components underlying the ELIXIR Interoperability FAIR Service Framework (see the Interoperability Platform page). The RIRs are identified as resources that facilitate the FAIR-supporting activities in scientific research, such as: Establish connections between data (and other) resources Acquire and expose metadata of data (and other) resources Create the infrastructure needed to build integratable data collections Use interoperability resources to support delivery of FAIR principles The portfolio of ELIXIR Recommended Interoperability Resources will be regularly evaluated for quality assurance and quality control. Further resources will be included in future calls for RIR application (next one in 2019) as ELIXIR evolves, accommodating emerging technologies and changing scientific needs. Recommendations for use of RIRs should also be recognised as suggestions and not a mandate as we value emerging developments from our ELIXIR members based on upcoming ELIXIR use case requirements.