100 years after the first observation of ripening by Ostwald and 40 years after the first publication of a theory describing this process, this monograph presents in a self-consistent and comprehensive manner, all the bits and pieces of coarsening theories so that the main issues and the underlying mathematics of self-similar coarsening of dispersed systems can be understood. Rather than giving a complete survey of the field, it presents a careful derivation of the existing results and places them into some perspective.