Book excerpt: Boundary spanning behavior is important for both public, non-profit and private organizations to ‘survive’: to stay relevant in relation to the environment, to innovate, to improve performance and to collaborate in an effective manner, especially in multi-organizational settings. Providing an assessment of factors influencing the work and effectiveness of boundary spanners, and discussing the impact of boundary spanners on different types of outcomes (collaboration, trust, organizational innovation), this book offers a coherent overview of the evolution of boundary spanning in an interactive governance context.