The dynamics of production, circulation and dissemination of knowledge that are currently developing in the digital ecosystem testify to a profound change in capitalism. On the margins of the traditional duo of knowledge markets and exclusive property rights, the emerging notion of cultural commons is opening the door to new modes of production based on hybrid market arrangements and an inclusive understanding of property. This book studies the political economy of cultural commons in the digital ecosystem, outlining the contexts and areas of thought in which this concept has emerged and identifying the socio-economic, technical and political issues associated with it. It also analyzes the specific physical conditions that enable the implementation of the economy of cultural commons in a specific digital ecosystem, that of books, by studying the effects of digital libraries and self-publishing platforms.