Carlos E.R. wrote:
I think I heard about a gratis version, perhaps online inside a browser.
Is this correct? If that is so, perhaps I should suggest my friend to
use that online version and not spend an euro.


https://support.google.com/docs/answer/6055139
Work with Office files

You can edit, download, and convert Microsoft® Office files in Google Docs, Sheets, and Slides.

To edit an Office file, you can either:

Edit the file using Office Compatibility Mode (OCM)
Convert the file to Google Docs, Sheets, or Slides.

Once you've edited a Google Docs, Sheets, and Slides file, you can then save and export it as an Office file to share with others.


The formats (from wp):
Files in the following formats can be viewed and converted to their Docs format:[34]

For documents: .doc (if newer than Microsoft Office 95), .docx, .docm .dot, .dotx, .dotm, .html, plain text (.txt), .rtf, .odt




--
Mike Easter