Commons are resources managed by a community for joint use. Since the late 1990s, new types of commons have emerged online. The core of these informational commons is created in four overlapping settings at the center of the information economy: free software, free culture, access to knowledge, and open data. Commons differ sharply from market-based or command-based modes of production, not the least through the relative absence of exclusive property rights, and the emphasis placed on cooperation rather than competition as the main driver of development. Thus, informational commons is one of the highly dynamic and contested areas in the information society.