Affect-aware technologies are moving the frontiers of how we understand, support, and optimize student learning. The authors explore five areas that exemplify cutting-edge research in the burgeoning field. These include intelligent tutoring systems that detect and respond to students' affective states and sometimes synthesize affect; the strategic induction of confusion as a means to stimulate deep learning; techniques to increase student engagement and reflection; systems that support the development of prosocial behaviors, resilience, and other aspects that contribute to students' well-being; and sample projects that highlight how these new ideas can be taken from laboratories into real-world classrooms.