Help+Manual's eWriter format is a fully viable replacement for the obsolete CHM format for software help. Particularly on Windows 10, where users automatically get the eViewer eWriter viewer app from the Microsoft Store as soon as they open an .ewriter file. And developers just need to include the compact Win32 eViewer application for compatibility with all versions of Windows from XP on up.
EWriter, which is really local WebHelp in a single file, can also be a good alternative to WebHelp for developers who need to install their documentation together with their applications. WebHelp can be preferable when it can be installed on your Internet web server. Then you can update your documentation at any time without having to redistribute.