So-called ‘semantic technologies’ are rapidly becoming mainstream technologies, with RDF and OWL now being deployed in diverse application domains, and with major technology vendors starting to augment their existing systems accordingly. This is, however, only the first step for Semantic Web research; we need to demonstrate that the semantic technologies we are developing can (be made to) exhibit robust scalability if deployments in large scale applications are to be successful. In this paper I will briefly review the evolution of semantic technologies to date, examine the scalability challenges arising from deployment in large scale applications, and discuss ongoing research aimed at addressing them.