CODE beyond FAIR: a roadmap for reusable research software

FAIR principles are a set of guidelines aiming at simplifying the distribution of scientific data to enhance reuse and reproducibility. This article focuses on research software, which significantly differs from data in its living nature, and its relationship with free and open-source software. We provide a tiered roadmap to improve the state of research software, which takes into account the full range of stakeholders in the research software ecosystem: all scientific staff - regardless of prior software engineering training - but also institutions, funders, libraries and publishers.