Book excerpt: Philanthropy – the use of private resources for public purposes – is undergoing a transformation, both in practice and as an emerging field of study. Expectations of what philanthropy can achieve have risen significantly in recent years, reflecting a substantial, but uneven, increase in global wealth and the rolling back of state services in anticipation that philanthropy will fill the void. In addition to this, experiments with entrepreneurial and venture philanthropy are producing novel intersections of the public, non-profit and private spheres, accompanied by new kinds of partnerships and hybrid organisational forms. The Routledge Companion to Philanthropy examines these changes and other challenges that philanthropists and philanthropic organisations face. With contributions from an international team of leading contemporary thinkers on philanthropy, this Companion provides an introduction to, and critical exploration of, philanthropy; discussing current theories, research and the diverse professional practices within the field from a variety of disciplinary perspectives. The Routledge Companion to Philanthropy is a rich and valuable resource for students, researchers, practitioners and policymakers working in or interested in philanthropy.