The years 2001-2016 mark the emergence and growth of the concept of global internet governance and related institutions and innovations. In 2001, the International Telecommunications Union (ITU) began to organize the World Summit on the Information Society (WSIS) which ultimately led to the creation of an institutional innovation, the Internet Governance Forum (IGF). In 2016, the eleventh Internet Governance Forum will be held, after the United Nations General Assembly decided in December 2015 to renew its mandate for ten additional years. This fifteen year period includes a kaleidoscopic array of actors and institutions (both old and new) related to the governance of the internet from national to regional to global levels. This paper provides a fifteen-year assessment of these developments, focusing on the role and strategies of actors in global Internet governance. Beyond the three main categories of stakeholders as usually identified in the field (governments, businesses and civil society), it focuses on those less explored actors, such as intergovernmental organizations, technical communities and other less organized categories. The paper studies the strategies undertaken by these actors including the forging of formal and informal alliances, in view of advancing their respective agendas and profiles in the field. It analyzes how they have been crafting or redefining their respective roles on the global scene throughout the main Internet governance meetings and venues. Using a multidisciplinary framework from political science, international relations, communication theory and organizational sociology, the paper roots its empirical findings in a longitudinal research project undertaken by the authors since the end of 2013. The methods used include interviewing key leaders of various organizations, analyzing documents and archival data from global Internet governance meetings and observing participation patterns at such meetings. The fifteen year assessment provided in this paper builds on intermediary results previously published by the authors, consolidating them and highlighting global Internet governance specifics as compared to other global governance fields.