The Microsoft Word DocX format is a proprietary file format used by the “Microsoft Word” word processing program. It is based on the Open XML standard and is designed to store documents as XML files. The HelpNDoc help authoring tool can generate help documentation in the DocX format and optionally in the RTF format too.
When it comes to creating high-quality help files, user manuals, documentation websites, or eBooks, Microsoft Word is not the best tool for the job. In fact, it can be a real pain to use and the results are often far from satisfactory: managing multiple interconnected documents with Microsoft Word is very hard, error-prone, and time-consuming. A Help Authoring Tool (HAT), such as HelpNDoc, is much simpler, faster, and therefore cheaper to use.
Microsoft Word, and similar word processing software such as LibreOffice, are great to write and format documents meant to be printed, but not so good at producing HTML websites from those documents: they generate suboptimal single-page HTML / CSS code which is not optimized for different screen sizes and devices such as smartphones.
By leveraging the import and export capabilities of a help authoring tool such as HelpNDoc (which is free for personal use), it is extremely easy to convert a Word document to a fully functional multi-page and responsive HTML 5 website.