While development debates have largely shifted away from the polarised view of ‘state versus market’, significant divergences in understandings and approaches remain about the roles and potentials of business, state and society actors. Underlying these differences are often implicit assumptions about the nature of markets themselves. This introduction first provides an overview of current broad lines of debate and their implications and then goes on to discuss the ways in which the articles in this IDS Bulletin provide more nuanced insights about the new actors, relationships and approaches. With questions remaining about the ability of business and market-focused initiatives to impact on social, environmental and economic aspects of development, the articles in this IDS Bulletin point to the need for approaches which are nuanced, experimental, bottom up and inclusive of multiple perspectives.