I’m not really a fan of writing in Scrivener with monospace fonts, but for those who are, iA Writer have a new open source font they have shared, and a blog post which describes their reasoning creating what they call a Duospace font:
Very interesting! Thanks for posting this. Sadly I spent too many years in the 60s-90s programming in monospaced fonts and I like it when things Just. Line. Up. Darnit. 
The wider Ms and Ws are yes, visually appealing, but…
My current monospaced love is Cousine, available free at Font Squirrel (https://www.fontsquirrel.com/fonts/cousine), my usual free font fix site. The really cool thing about the font, aside from the facts that it’s free, and it lines up at 10 chrs/in in 12 pt, and 12 chrs/in in 10 pt. exactly, is that the glyphs are so distinguishable. There is a clear distinction among capital i, lowercase L, numeral 1, and vertical bar. Similarly, capital o and numeral 0 are sharply distinct, as are hyphen, en-dash, and em-dash. The Courier variants suffer from typewriter holdovers because so many old keyboards lacked numeral 1, numeral 0, vertical bar, and had no dash glyph but a hyphen. The sans serif mono fonts vary on this, but Cousine is the best free font I’ve found. The problem glyphs at 12 point:
The distinction among the dash glyphs is wonderful in Cousine. Courier Prime—it’s OK for output for beta readers. I’ll use Ubuntu Mono if I need a condensed font. The others lack bold, italic, and/or bold+italic variants.
Monospaced fans, enjoy! Or try the Duospace font if you’re not as picky as I am…
I like these – thanks to both of you for sharing.
I don’t know, Silverdragon, Duospace may be clocking your Cousine on that score, at least:
I grant you, @gr, that the Duospace hyphen glyphs are nice, 
even nicer and more distinct than Cousine’s. But there it is, Duospace won’t line up if an M or a W (upper or lower case) is used. As I said, if I weren’t so picky about that, Duospace is great, and I’d switch.
But as it is, Cousine serves my humble purposes.
@silverdragon: you are indeed truly worthy of the title “monospace lover”!!! 
I humbly bow in honour of your quest for consistent glyph dimensions…
blushes 
Thank you!
But iA Writer are right, you know. A monospaced font says “Not finished yet.” My manuscript needs to yell that at me.
p.s. I downloaded iA Writer Duospaced last night. There are some minor differences at smaller font sizes, but really in most sizes the problem glyphs look almost identical. Strokes tend to be a trifle heavier in Cousine. I prefer heavier, because none of my Mac screens is “retina” yet…
Gosh, it must take a keener eye and a calmer hand to glyph slice so finely! My eye just kept stumbling over Duospace’s lowercase ‘r’ which can’t decide if it’s coming or going. It registers with me as a kind of typographic affectation – undesirable for its intended use.
It could be argued that the vertical stretch of the letter shapes is a subtle concession to this-is-publishable-doneness. Oh what a slippery slope we slide when first we stoop to font design!
Some typographical geekiness in me is drawn to this Cousine just because of the promise of the perfect fit of characters per inch even though I have absolutely no need of such fittedness. Sometimes I just want to tell me mind to knock it off!
-gr
P.S. I find my desire for Courier personally puzzling. Its association with manuscript is clearly historical and in that sense ephemeral. Why would my manuscript Gestalt get stuck there, for heaven sakes? I mean, I have a perfectly good custom font of my own handwriting, but I certainly don’t use that for manuscript work. Go figure.
Indeed. I downloaded both the fonts suggested. Duowhatsit is nice, but that ‘r’ seems completely out of place, and once I’d noticed that I can’t unnotice it. Cousine doesn’t jar in the same way. Not sure either of them are much better than Courier Prime; in any way that I can see.
I’ve been following the advice on https://practicaltypography.com and tend to use Charter for serif, Fira Sans for non-serif and Courier Prime for monospace.
But in reality, this is pure moggie-hoovering on my part because I’m not really a designer and most of the subtleties pass me by.
“moggie-hoovering”? I know enough British idiom to know moggie=cat and hoovering=vacuuming, but what is moggie-hoovering?
Just another 2ç. Courier Prime is nice for a manuscript output. My standard font in the editor is the slightly less “typewritery” Courier Prime Sans.
EDIT: Published the wrong font first time 
Ah, sorry. I didn’t realise moggie was purely BrEng – or hoovering for that matter.
It’s just my take on the ‘real’ term – cat vacuuming: something unnecessary you do when you really ought to be writing.
That amusingly ridiculous term had me scrambling. I’m glad someone (else) asked. I had come to an entirely more uncomfortably sychophantic interpretation.
Hah!
Cat-vacuuming is quite an old term now – I think I first came across on the old Usenet group misc.writing in the 90s but it’s probably a lot older than that.
I downloaded Duospace from GitHub but after I installed it my Scrivener wouldn’t load at all.
I get the following error in the log:
Since then I removed the font and have no problems opening Scrivener.
I wonder if someone else encountered the same problem.
I didn’t import Duospace into Windows (I’m on Mac). There are a couple of reported issues doing so:
github.com/iaolo/iA-Fonts/issues/6
If you haven’t, definitely try Cousine. Silverdragon linked to it in an earlier post. Love it.
Thank you Silverdragon and nontroppo. 
Have you ever tired to hoover a cat? If not, I dare you to try it.
ROFL!!!
A well-placed kick in the knickers for me! As you may have guessed, I’m mildly OCD exacerbated by decades of software development where the difference between an el and a capital eye, or a capital oh and a zero could be critical—and before the days when syntax highlighting or spell checking were available, either one. Though even before that, I insisted my parents buy me a typewriter for college that had a Real Numeral One key, because using lowercase el instead bothered me for no logical reason… obviously I was destined to be a programmer even then. 
My major disappointments in Courier Prime are that I can’t glance at a large oval glyph and tell if it’s a capital oh or a zero, or look at a dash glyph and see whether it’s a hyphen or an en-dash. If not for that, Courier Prime would be my writing font, and it’s definitely my send-out-for-review font unless otherwise requested. And yeah, that Duospace lowercase r is hosed.
That said, I need to stop moggie-hoovering and get some writing done.
It wasn’t aimed at you — it was aimed at me!
I believe the modern vernacular is now “cat-waxing” – at least, that’s what I see being used today.