The composition of a country’s innovation system and the quality of interactions between the main actors in innovation have major implications for innovation performance and influence the mix and balance of policies needed to improve the overall innovation performance. Deriving appropriate policies therefore requires a systemic approach. With this perspective in mind, this chapter provides an overall characterization of the innovation and research activities of the business sector, public research institutes and the higher education sector, complemented by an assessment of intermediary institutions. It begins with business firms which are the central actors in advanced innovation systems, but in order to play this role they first need to build and develop the necessary capabilities in the process of development. The sectoral dimension plays an important role in this context. Next, attention is drawn to the system of public research institutes, including its current state, governance and funding, as well as its prospective role. It next turns to the higher education sector. A final section covers the relatively young set of intermediary institutions which play a role in linking the research sector and industry.