Single Source is ideal for developing the user documentation for an application. You can use it to create paper, Windows help and HTML documentation from a single source. Many tools exist that would appear to do the job, but unlike Single Source they tend to be limited in the automatic creation of the following: - "What s This?" help, obtained from low-level sections that have a particular heading style. - MAP file, allowing you to link a Help file to the application it documents. - Help Contents file, derived from the Table of Contents in the source document. - Related Topics list for each topic, derived from the primary keywords in the index terms for the topic. When reading a topic in the Help file, you can click a button to display a list of topics that are related to it. - Hypertext links, derived from cross-references (for both Help and HTML). - Help index, derived from the paper document index. Single Source requires the Microsoft Help Compiler, which you can download from the internet, and Microsoft Word.