[te0006]

This brings back fond memories from the 8-bit era. Tasword II was a text processor for the Sinclair ZX Spectrum where the developers resorted to extra-narrow fonts to cope with the Speccy's very limited (256x192) screen resolution. The lower screenshot in [1] provides a glimpse of what seems to be a 3px wide font.

OP's 2px width are a bit too extreme for my taste though.

[1] https://spectrumcomputing.co.uk/entry/4000080/Timex/Tasword_...

[reaperducer]

Similar to VIP Term on the Commodore 64, which used a 3x7 bitmap font in a 4x8 space to display 80-column text.

I don't know is any word processors did that, though, except in printer preview mode.

[classichasclass]

Pocket Writer (version 2, at least). Used it heavily for term papers.

[mrspuratic]

One of the first Spectrum emulators (JPP?) used a VGA text mode with 2 pixel high font where each character was its own ordinal, i.e. 65 was two rows of 01000001 pixels. That meant you could draw individual rows bytewise exactly as the Spectrum did, and just take care of the Y offset bit shuffle, and fake the colour clash.