Almost all text processors support keywords, which are used to derive the index of a book or a document. The index generally has to be generated when the document is finished and regenerated each time it is changed. Supporting an index in HelpServer is a piece of cake: all you have to do is to add keywords in the topics. The index is automatically generated the moment it is requested in the web browser or during a print operation. In this way the index is always up to date.
In stead of 'keywords' we use the term 'index object'. Also, HelpServer does not visualize the index in the Workbench. And index is only applicable when browsing content in the web browser and when printing or exporting content.