Today, software plays a crucial role in advancing and accelerating state-of-the-art academic research. It is therefore important to adhere to proven best practices when developing research software, as it will help avoid errors, improve maintenance and sustainability, while accelerating the overall development process. Also, it will help other researchers to better understand the intricacies of the software, and the analysis performed with it. This is an important prerequisite for reproducibility of scientific results, and it will allow other researchers to adopt the software into their own workflows, possibly even contributing to the software or expanding it. To promote the practice of Open Science, and the principles of FAIR data and software, the Netherlands eScience Center actively participates in the National Platform Open Science. In line with this initiative, the eScience Center strives to make the software developed in the projects it participates in to become freely and sustainably available, as much as possible, for reuse by other researchers. To this end, the Principal Investigator of every project (co-)funded by the eScience Center is required to submit a Software Sustainability Plan, i.e. a document that makes explicit the researcher’s foreseen actions regarding software sustainability.