Reconceptualising what the public service enterprise in media should be about in the 21st century has been thematic in the first decade of this century. The growth of a market-based orientation in mediation, increasing competition in both traditional and maturing media alike, concerns about audience fragmentation and implications for democracy and citizenship, together account for intensifying concern about the public interest in media today. The range and complexity of challenges are certainly evident in the series of RIPE conferences and books since 2002. In recent years discussion about the renewal has focussed increasingly on public participation as an integral but often problematic aspect of the transition to public service media [PSM]. This is in accord with deepening understanding that the viability of the public service enterprise depends on the degree to which the people paying for it and using its services consider it worth the price. This fourth RIPE Reader demonstrates how the historic insularity of PSB companies is changing as a new generation struggles to restructure and revitalise the public service enterprise in media against a backdrop of continuing PSB legacies, in both its assets and its liabilities. The collective contents document the significance of engaging the public in, with and through media services, arguing the crucial importance of the Public in Public Service Media. The contents draw from discourse and development of research presented in the RIPE@2008 conference in Germany, which was titled Public Service Media in the 21st Century: Participation, Partnership and Media Development. The authors included in this collection query what any serious effort to achieve participation-readiness requires of a public service media company in many interdependent facets: strategy revision, organisational restructuring, retooling production processes, and redefining professional identities. This is approached in two sections, the first focussed on theories and trends that are to the topic and the second focussed on practices and performance to date.