FAIR-USE4OS: From open source to Open Source

This paper extends the FAIR (Findable, Accessible, Interoperable, Reusable) guidelines to provide criteria for assessing if software is Open Source. By adding 'USE' (User-Centered, Sustainable, Equitable), software development can adhere to open source best practice by incorporating user-input early on, ensuring front-end designs are accessible to all possible stakeholders, and planning long-term sustainability alongside software design. The FAIR-USE4OS guidelines will allow funders and researchers to more effectively evaluate and plan Open Source software projects. There is good evidence of funders increasingly mandating that all funded research software is open-source; however, even under the FAIR guidelines, this could simply mean software released on GitHub with a Zenodo DOI. By employing the FAIR-USE4OS guidelines, best practice can be demonstrated from the very beginning of the design process and the software has the greatest chance of success by being truly 'Open Source'.