the book is a fairly complete and up-to-date survey of projectivity and its generalizations in the class of boolean algebras. although algebra adds its own methods and questions, many of the results presented were first proved by topologists in the more general setting of (not necessarily zero-dimensional) compact spaces. an appendix demonstrates the application of advanced set-theoretic methods to the field.the intended readers are boolean and universal algebraists. the book will also be useful for general topologists wanting to learn about kappa-metrizable spaces and related classes. the text is practically self-contained but assumes experience with the basic concepts and techniques of boolean algebras.