Discussing results of our joint project that examines the complex interactions among intergovernmental organizations and other transnational institutions and nonstate actors in the global Internet governance ecosystem, this study highlights themes related to the changing architecture and roles of international organizations from WSIS (World Summit on the Information Society) until NetMundial. Attention is paid to old and new categories of organizations that emerged in this context; and how they have been recognized as stakeholders in the process. These organizations form a network, set in an environmental context, thus constituting the interorganizational infrastructure for internet governance today. Additionally, tracing knowledge flows and power differentials over time among the different stakeholder organizations helps to illustrate a major finding, the pro-active role of the international organizations studied here in the messy, complex, and cross-national internet governance ecosystem, shaped by and, at the same time, shaping the technical infrastructure.