Sustainability and interoperability: Two facets of the same gold medal

'To sustain is to endure' - that is, to be able to survive and continue to function in the face of significant changes. The commonly accepted concept of 'sustainability' currently encompasses three main pillars: environmental, social/ethical and economic. In a metaphor of survival, they can be seen as water, food and air; one needs all three, only with varying degrees of urgency. In today's globally networked environment, it is becoming obvious that one cannot achieve environmental, social or economic sustainability of any artefact (be it physical or virtual, e.g. enterprise, project, information system, policy, etc) without achieving ubiquitous ability of the artefact and its creators and users to exchange and understand shared information and if necessary perform processes on behalf of each other - capabilities that are usually defined as 'interoperability'. Thus, sustainability relies on interoperability, while, conversely, interoperability as an ongoing concern relies for its existence on all three main pillars of sustainability. This paper aims to test the hypothesis that interoperability and sustainability are two inseparable and inherently linked aspects of any universe of discourse. To achieve this, it applies the dualistic sustainability / interoperability viewpoint to a variety of areas (manufacturing, healthcare, information and communication technology and standardisation), analyses the results and synthesizes conclusions and guidelines for future work.