This chapter provides an overview of the concepts of collective invention, user innovation, and open innovation. All three notions represent variants of distributed innovation and can be linked to other ideas of socioeconomic decentralization. The following sections first elaborate on the conceptual differences between collective invention, user innovation, and open innovation. Second, exemplary case studies from the last few decades are presented before more recent varieties of distributed innovation in the development of information technologies are discussed. In this area in particular, it becomes clear that distributed innovation processes and internal research and development activities in organizations are less in competition with each other than in a complementary relationship.