Do you need to maintain a single-page version of a multipage HTML document? if the document is composed completely of HTML documents in a flat directory that use the same CSS style sheet, you can get good results by simply merging all the files using a page nearly identical to this. In fact, you can save the source of this page and just change the filenames in the loadthem() function to try out the method.
The merged files' header sections are essentially ignored, meaning this does not work well unless all the sections use the same style sheet and are all in the same directory or do not use other files (such as images) by a relative pathname.
This method has an advantage over scripted solutions available to Unix users using simple scripts and utilities such as sed(1) to merge the files. The only time you have to edit the file is to add or delete sections, for example. Some Internet Providers provide WWW servers that let you do something similar (very much like the cpp(1) (ie. the C preprocessor) "#include" directive). But this simple merging of files does not let you reproduce a complex document any better than the method shown here.