Dialectology is the study of dialects, and dialectometry is the measurement of dialect differences, i.e. linguistic differences whose distribution is determined primarily by geography. The earliest works in dialectology showed that language variation is complex both geographically and linguistically and cannot be reduced to simple characterizations. There has thus always been a perceived need for techniques which can deal with large amounts of data in a controlled means, i.e. computational techniques. This special issue of Computers and the Humanities presents a range of recent work on this topic.</p