IntroductionThis chapter highlights a particularly challenging arena for knowledge governance, by focussing on the governance issues associated with large-scale programmes of what has been termed 'open innovation'. As outlined in more detail below, open innovation -also sometimes labelled synonymously as 'networked' or 'distributed' innovationis an increasingly important component of the wider patterns of innovation in advanced economies. It can be seen in large part as a response to firms' increasing needs to draw on external sources of knowledge in order to remain competitive in a global economy.Issues of knowledge governance are at the heart of open innovation inasmuch as such innovation is acutely dependent on the organization of knowledge flows between and within firms. The ability of firms to acquire externally-sourced knowledge has been a major subject of academic debate since the pioneering work of Cohen and Levinthal on 'absorptive capacity', and Von Hippel's studies of userdriven innovation (Cohen and Levinthal 1990;von Hippel 1988). However, the distinctive challenges posed by an avowedly open approach to innovation processes are still being digested by researchers. These challenges go some way beyond the problem of absorbing knowledge. According to its proponents, open innovation involves a qualitative shift in the way the firm creates, exploits and organizes knowledge. This has wide-ranging implications for the way the focal firm manages itself and its knowledge-base. At the very least, open innovation implies a reduced dependence on internal R&D functions and a greater willingness to trade knowledge with external collaborators. More broadly, though, the serious pursuit of open 2 innovation is likely to extend to radical changes in the structure and management practices of the firm to foster greater interactivity with the expanding ecology of knowledge providers.It is not within the scope of this paper to address all of the many challenges which open innovation creates for established governance arrangements. Rather, our aim is to provide an initial exploration of some of these challenges by analysing a casestudy of a more open form of innovation. This is an important but also especially complex case because it has to do with MOZART 1 , one of the major collaborative research programmes sponsored by the European Union (EU). This programme represents a unique institutional response to the needs of the aerospace industry in Europe, reflecting not only the diverse needs of the participating companies but also the strategic interests formulated by the EU as a political body. As such it raises the challenges of knowledge governance to a new level, since it encompasses not only questions of effective governance for an innovation process, and the inter-firm collaboration underpinning it, but also the wider challenge of linking private enterprise with the strategic objectives of multi-state bodies. The remainder of this chapter then proceeds as follows. We begin, in the following section, by identifying the...