To open and view a .chm (Compiled HTML) file on a Mac running macOS, you can use a third-party tool such as Chmox. Chmox is a free, open-source tool that allows you to view .chm files on macOS.
To install and use Chmox, follow these steps:
Download the latest version of Chmox from the project's website at https://chmox.sourceforge.io/.
Double-click the downloaded .dmg file to mount it.
Drag the Chmox app from the .dmg file to your Applications folder or to the location where you want to install it.
Launch Chmox by double-clicking the app icon.
In Chmox, click the "Open" button and select the .chm file you want to view.
The .chm file will be displayed in the Chmox window. You can use the navigation pane on the left to browse the contents of the .chm file, and use the search function to find specific topics.
Note that .chm files may not display correctly in some versions of Chmox due to a limitation in the way that macOS handles .chm files. If you are having trouble viewing a .chm file, you may need to try a different tool or convert the .chm file to a different format.
Alternatively, you can use a web browser to view .chm files by converting them to HTML using a tool such as Chmox or 7-Zip (a free, open-source file archiver). To convert a .chm file to HTML using 7-Zip, follow these steps:
Download and install 7-Zip from the project's website at https://www.7-zip.org/.
Open 7-Zip and navigate to the .chm file you want to convert.
Right-click the .chm file and select "Extract to...".
In the "Extract to" dialog, select a destination folder for the extracted files and click "OK".
The .chm file will be extracted to the specified destination folder as a set of HTML files. You can then open these HTML files in a web browser to view the contents of the .chm file.