The hyper-links that join different HTML pages within hypertext documents are normally defined by the document's author. These are an internal matter - if the document structure changes, the author can change the internal links accordingly. If proper use is made of relative file names in establishing these links, it should also be possible to transport these documents as a whole to a different location without damaging the internal links.
HTX addresses the different problem of maintaining a collection of dynamic hypertext documents (probably written by many different authors) that have cross-references established between them. That is, each document may contain hyper-links to the contents of any other document in the collection.
In this situation, document locations may often need to change, and revision of individual documents will also result in the referenced material moving around within them. Since the links that implement HTML cross-references consist, essentially, of file names, they cannot survive this process and will rapidly end up pointing to the wrong places unless remedial action is taken.
In a large document collection, re-organising all necessary
cross-references following every document change is not a task to
contemplate doing by hand. Establishing and repairing these links is
therefore a job for the HTX hypertext linker.
HTX Hypertext Cross-Reference Utilities