This book provides an in-depth discussion of the field of syntactic wordclass tagging, i.e. the annotation of the words in a text with tags indicating their syntactic properties. Represented are the viewpoints of the two main groups who take an interest in tagging: the users of tagged text and the developers of tagging software. The book starts out by examining the field foremost from the user's point of view. After a brief historical overview, the nature and uses of tagging are discussed and current practice is described. Here the user will find what tagging is and the software developer what it is the user wants. The book then switches to the other point of view and continues with a detailed explanation of the most common computational techniques for automatically tagging large amounts of text. Here the software developer finds information needed for the implementation of a tagger while the user gains insight into the possibilities and impossibilities of automatic tagging and how computer-provided tags should be interpreted.