Writing documentation is an integral part of any technical product development. A significant amount of time is spent describing the product functionality, giving insights into technical details, providing maintenance instructions, specifying marketing information, writing user manuals, etc. As the creation of such documentation is generally a source of higher production costs, many large companies are realising the need to increase the efficiency of documentation handling. Simple documents consisting of only a few pages can be developed on simple systems. Basic components of such systems are an editor handling text and graphics, file storage, and a printer. Such configurations, however, are not sufficient to handle professional documentation as produced by larger companies. Detailed studies of technical documentation requirements have revealed that in particular the following functionality is not usually provided by such simple documentation systems: Technical documentation is often very large; documents having hundreds or even thousands of pages are not exceptional. Due to size and complexity, technical documentation is developed most often by a team of authors. A system for technical documentation has to provide functionality supporting the organisation of a group of authors. Technical documentation usually consists of many different documents combined into one large documentation for a particular product. The optimum organisation of the storage and retrieval of documents is crucial for the performance and acceptability of the system. The functionality offered by normal file systems is not adequate to organise complex systems.