I am looking for a product that can be used to create HTML help systems (.CHM files). I am aware of a product from West Wind Technologies called "HTML Help Builder". Does anybody have good or bad things to say about it? Does anybody know of competitive products that have advantages over the West Wind product?

It has recently occurred to me that I have never seen a web application with an on-line help system like you might find in a Windows app. Does anybody know of an example of one that I can look at?