The introduction provides an overview of the state-of-the-art and situates the diverse research experiences and theoretical perspectives discussed by the volume contributors. Moreover, it presents different ways to define language activism based on various theoretical perspectives, research experiences and socio-political contexts. In order to present a nuanced and comprehensive view of activism, the introduction includes a special focus on the different forms it takes, the various stakeholders who may be involved, the unpredictability of who is included and excluded, and the inescapably ideological nature of language and language research. The introduction also addresses the kinds of questions scholars ask depending on the nature of their scholarly and political agendas and lays out a rationale for the four-part organization of the volume. The volume contributions deal with varied social settings ranging from contexts marked by great socio-economic and political inequality with sharply defined power hierarchies, to more egalitarian contexts with more dispersed power and subtle and diverse power hierarchies. Language struggles, whether they involve endangered language revitalization, language standardization, spelling reform or other efforts, involve numerous stakeholders and lead to tensions and battles among as well as within groups.