The Intelligent Documentation Advisory System generates on-line documentation and help messages from a domain knowledge base, using natural-language (NL) generation techniques. This paper gives an overview of IDAS, with particular emphasis on: (1) its architecture and the types of questions it is capable of answering; (2) its KR and NL generation systems, and lessons we have learned in designing them; and (3) its hypertext-like user interface, and the benefits such an interface brings.