I use vim with the Copilot plugin.
It's pretty astounding what it spits out.
I was writing a handbook for a credit union board of directors and it was quite helpful at times.
Copilot is designed for code, but it can still be used for whatever you want. I found it useful when writing latex files, even for the text explanation portions as opposed to the text markup 'code'. There was a y combinator thread on this earlier.
