Typology research is extremely important in both proposing classification frameworks and in promoting the careful investigation and analysis of the core concepts inherent within the classification contrasts employed. More exemplary of the latter aspect, the present collection of papers on the typology of writing systems address a number of significant linguistic and psycholinguistic issues surrounding the classification of writing systems. The seven contributions within this volume, which originally appeared as a special issue of Written Language and Literacy 14:1 (2011), cover a wide variety of issues, ranging from an overview of writing system typology research, comparative graphematics, letter-shape similarities, the morphographic principle, tone orthography typology, measuring graphematic transparency, to unconventional spellings within online chat.