How does it work?

XMLmind Web Help Compiler works a little like hhc.exe, Microsoft® HTML Help compiler. It takes as its input:

A number of XHTML (i.e. plain HTML won't work) input pages.
Optionally a Table of Contents specified by an XML input file.
This XML input file must conform to the following RELAX NG schema: schema/toc.rnc. A sample TOC XML file is found in toc.xml.
Optionally some Index entries specified by an XML input file.
This XML input file must conform to the following RELAX NG schema: schema/index.rnc. A sample index XML file is found in index.xml.
For now, the toc.rnc and index.rnc schemas are not documented. We'll document them as soon as someone will be interested.

Unlike hhc.exe which generates a single ".chm" file, whc:

Copies the XHTML input pages to its output directory. However it does so after “decorating” the XHTML input pages. By decorating, we mean that whc adds a reasonable number of XHTML elements to each XHTML input page. For example, it adds:
```
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
...
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js" 
       type="text/javascript"></script>
<script src="_wh/wh.js" 
        type="text/javascript" charset="UTF-8"></script>
...
<head>
...
<html>
```
More precisely,
- Whc script elements are inserted before first page script element if any; appended to the head element otherwise.
- Whc link rel=stylesheet and meta elements are appended to the head element.
Copies a number of resources (CSS stylesheets, JavaScript files) referenced by the decorated XHTML pages to a _wh/ subdirectory of its output directory.

XMLmind Web Help Compiler Manual