The publication of this edited volume comes at a time when interest in the acquisition of phonology by both children learning a first language and adults learning a second is starting to swell. The ten contributions, from established scholars and relative newcomers alike, provide a comprehensive demonstration of the progress being made in the field through the theory-based analysis of both spontaneous and experimental acquisition data involving a number of first and second languages including English, French, German, Korean, Polish and Spanish. Aimed at those active in phonology and its acquisition, yet written to be accessible to the non-specialist as well, the volume carefully lays out the various theoretical frameworks in which the authors work such as Feature Geometry, Lexical Phonology, Non-Linear Phonology, Prosodic Phonology, and Optimality Theory.