The emergence of new modes of collaborative innovation that are characterized by a decentralized coordination of many individuals rather than the strategic integration of distributed external knowledge into the innovation process on the part of private enterprises or public institutions, reshapes the innovation landscape fundamentally. The increasing relevance of so-called peer-to-peer innovations is triggered by the new technological possibilities for communication and interconnectedness as well as by an increasing need for non-technical solutions to cope with the great societal challenges of sustainability. With this, civil society arises as the fourth subsystem of the innovation system besides academia, industry and government, and partly takes over essential system functions. These changes in innovation practices call for new steering models and regulatory framework conditions. Open infrastructures for interlinkage, exchange and coordination of many are becoming the linchpins of this development.