Our educational systems as we know them today evolved in a physical context defined by scarcity. The constraints of the physical realities of schools of various types – agora, one-room schoolhouses, and more modern schools of all types – and the need for all students and teachers to gather in one place at one time set limits on the availability of teaching, space, time, and resources. The advent of ubiquitous networked devices that cheaply connect us with one another, and with the reified interactions and the content we create, has greatly diminished such constraints, as have new pedagogies more suited to these open and connected learning environments. We are only beginning to adapt our educational systems to fit this new, less rivalrous, less bounded, more open reality. This chapter describes some of the main features of this more open universe, explores the different kinds of openness that are enabled, and describes some of their consequences for primary and secondary educators and learners.