This paper reports on the development of QoSOnt: an ontology for Quality of Service (QoS). Particular focus is given to its application in the field of servicecentric systems. QoSOnt is being developed to promote consensus on QoS concepts, by providing a model which is generic enough for reuse across multiple domains. As well as the structure of the ontology itself, an example application currently in development - SQRM (Service QoS Requirements Matcher) - is discussed. This application is used to highlight some of the advantages of the ontology including standardisation and the level of machine understanding of QoS specifications which can be achieved.