I hate to say this because Nisus was my first Mac word processor. No, actually, I used Pages for a while. Then Pages changed and a mail merge script that I liked stopped working. Nisus was my second word processor.
Nisus Writer is (was) a pretty big name in the Mac universe. I believe it's safe to say it has become abandonware. Customer support isn't reachable. One of the two or three active threads on the Nisus forums is titled "Is Nisus moribund" and there has been no input or response from Nisus.
Automated sales processes still work so it remains possible to buy a new copy of Nisus. My opinion, beware. Something not good must have happened behind the scenes.
To any who use Nisus, its RTF files are non-standard rich text. As far as I know, anything that reads RTF files can open and modify Nisus documents. When another editor writes a Nisus file, Nisus styles in the document will be replaced with generic RTF styles. Or something like that.
Nisus doesn't read docx perfectly and I've seen docx export create unusable Word files. If you export to docx, confirm you got something close to what you expected.
Personally, I think it's a crying shame there isn't an enhanced Markdown allowing more formatting options. A little of the power of LaTex in a markup lingo with the casual ease of Markdown would be a good thing.
I would be happy writing with vim or BBEdit. In fact, when I write for complex formatting (or outrageous tinfoil hat tabloid pamphlets), I like BBEdit's Notebook files. They are sort of like a mini-Scrivener in plain text. Copy and paste from BBEdit to Affinity Publisher works like a champ, and I prefer pasting plain text to docx files in Affinity.
That's, of course, a lot of work to dash out a quick letter.
I've never had any trouble with converting those files to doc/docx, so I'm not sure what you mean, Naomasa.
