Language policy and planning has a long history, but an explicit theoretical framework has only developed in the last fifty years. The process is regarded in a unitary way, and called language planning, while the decisions involved constitute language policy. Tollefson (1995), Hornberger (2008) and others discuss planning and implementing supportive policies for minority language education and cultural maintenance. Chapter 9 investigates planning related to reclaiming endangered languages; see also Hinton (2001a, 2011), Hinton et al. (2002), Lewis and Simons (2015b), among others. For a number of relevant case studies, see Hinton and Hale (2001), and Hinton, Huss and Roche (2018).