In order to address open, distributed, and knowledge-intensive scenarios, we introduce a semantic-oriented extension of the tuple centre coordination model. There, each tuple centre is extended with the ontological description of the coordination domain, expressed by means of the W3C standard OWL. Unlike existing approaches in the literature, our coordination model smoothly extends the standard syntactic setting of tuple spaces, allowing the coordination behaviour of tuple centres to be semantically programmed. A testbed implementation of our model in the TuCSoN infrastructure featuring the Pellet semantic reasoner is described, and its performance is evaluated and discussed.