Manipulation of text by means of the computer is well-established. Everybody has a word processor on his or her desk, and electronic mail, desk top publishing, text interchange languages, hypertext and multimedia are technologies many will be aware of. However, the full potential of the computer for the management and use of textual information has not been tapped yet. Far from it. For this a more principled approach is necessary, which will create a framework on which existing technologies, and technologies-yet-to-come can build and in which they can be integrated. This book can be seen as one step on this road. It employs the experience gained in working with a rich electronic linguistic corpus, the ECA database. A basic text database model is put forward and several text database retrieval languages are defined and analysed. A clear direction for further research is given. Therefore, the book is of relevance to researchers and developers in the field of corpus linguistics and in the more general field of electronic text.