Hah: I am very particular about fonts myself but what bugs me most isn't sub-pixel hinting (which is "good enough" with the latest freetype IMHO) it's the size of fonts. Windows is so far off the mark on 99% of computers and it drives me crazy!

Repeat after me:

    72pt is one inch tall!
    72pt is one inch tall!
    72pt is one inch tall!

The "point" scale of fonts is actually a precise, real-world measurement like inches, millimeters, etc. Fonts may differ in how much space each glyph takes up but in general they should at least be close to the correct size.

Test it: Open up a word processor and load some reasonably normal font (e.g. Arial) and make some text that's 72pt. Then hold a ruler up to your screen: Is it about 1 inch tall? How far off the mark is it?

If you're using a modern, high-DPI display it's probably waaaaay TF off, haha. Even with regular displays it'll be off and there's actually no way to fix it because you can't tell Windows the precise DPI of your display! It tries to guess based on the DDC data given by your display but then averages the X/Y together to scale fonts. So if your X DPI is higher than your Y DPI it'll always get it wrong. Always!

Macs cheat in this area by always having displays of a fixed DPI. For the longest time all Apple displays were precisely 96 dpi (with perfectly square pixels) but recently changed it to 220-ish and made adjustments in their font rendering engine to match. I have no idea how they're handling non-Apple displays these days.

Linux, on the other hand does it right (at least X11 and KDE do) in that it scales fonts very accurately based on the DPI presented by your display via the DDC protocol (or if your monitor doesn't provide that you can set both X and Y DPI manually).

Gnome and GTK applications have the same problem as Windows though in that they only take one DPI setting and if the DDC protocol gives separate X/Y values it'll just average them and the results can be... Ridiculous. You don't really notice the weirdly-stretched fonts until you open a KDE application side-by-side with a GTK one.

On top of that mess you describe here lives the web designer pixel mess.

Web designers loved to do their web pages with pixel measurements instead of real lengths in millimeters or points. Which is a horrible idea because of the different DPIes.

DPIes became bigger and bigger over time and browser developers were between two fronts of bullshit. The OS told them a bullshit DPI and web pages gave them a bullshit pixel length design. What did they do? The invented a third layer of bullshit to fix the other two (a little): the fake pixel. "Pixels" in web pages today have not the same length like the screen's real pixels, they are somehow scaled.

This is all broken beyond repair.

I wished that browser developers would have implemented it the right way. A pixel is a pixel and an inch is an inch. Many sites would be broken after that and the web designers would be forced to fix that and to use for example millimeters or points for lengths. And in a perfect world the OS would then use the correct DPI to display the rendered result.

I have never seen a display with non-square pixels, except maybe on cameras. Where are those typically installed?

CRT monitors will naturally display non-square pixels, depending on the resolution. Sometimes LCD's are run in non-native resolution due to GPU or driver issues, which results in a stretched display where the input pixels are not square.

CGA displays had non-square (logical) pixels. The ratio for 320×200 resolution is 1.6, but it is shown on a 4:3 (1.333) screen.

Where can I read more about how 72pt ~ 1 inch? Where does one g to for a "course on typography"?

This was posted recently: https://tonsky.me/blog/font-size/

Wow, first time I hear that as the main and apparently only argument to using Windows over any Linux distro.

With HiDPI displays all over the place, is subpixel rendering really still a thing? Pixels have gotten so small, I can't see individual ones anymore even if I'm trying. They could leave out anti-aliasing altogether in fonts and I'd hardly notice.

Or I'm just getting old.

I think that people are just too fussy. I have anti-aliasing disabled on my 142 dpi laptop screen and it looks better in most applications provided that screen fonts are used. Yes, you can see the pixels and you get the odd rendering artifact. On the other hand, the fuzziness of anti-aliasing is a steep price for edges that appear smoother.

Most desktop environments will offer subpixel AA, and with GNOME and KDE, I think it's enabled by default.

FreeType and slight hinting + subpixel antialiasing looks great to me, really... Windows has strong pixel-fitting and at the same time softer outlines. That is after using the ClearType tuner to tweak it to my liking. I'm not particularly fond of that look. You talk about hardware. The gamma of your screen makes a difference - antialiasing relies on it. The ClearType tuner has a page or three about that. I guess on Linux you better set your display gamma to the standard value, there is no good reason (except visual impairment or something) to set it to anything else anyway.

By the way, font rendering in Chrome for Linux used to be really awful (no subpixel AA or something). It was fixed a few years ago - it looks like any other app now.

I omitted some detail that you can easily find in your favorite search engine.

I’ve changed entire distros, back in the day, based on font rendering. However, you’re on crack if you think Windows fonts are great. MacOS makes everything else look like children’s scrawl. I’ve been running on Macs for about 6 years now (with a PC connected to the same external monitor) and I still sometimes just stop and admire how nice the fonts are.

I have a 4K and 5k display, and I find it as pleasant as my 2019 MacBook. I’m not sure if it’s because I’m not sensitive to it, or what. (I’m using Fedora with Gnome 40.)