I guess what @loucheman means, or at least I would find it useful, is a list of fonts available on all major platforms - such that when used in a (shared, published) Snap! program they will be recognizable for most every user.
You can also try these fonts that work on certain devices:
- Bahnschrift
- Corbel
- Tahoma
Or some of these fonts that are from Google Fonts:
- Lato
- Montserrat
- Rubik
- Merriweather
Bahnschrift, Corbel and Tahoma look different
Lato,Montserrat, Rubik and Merriweather look the same
That's because the font is not installed on your computer.
That's asking a lot. Maybe FreeSerif, FreeSans, and FreeMono? The more strict GNU distributions won't include commercial fonts. Does Windows have the Free* ones out of the box?
There's an OfficialRightThing for this situation, namely, to set the font to Serif, Sans-Serif, or Fixed-Width. Those generic names allow the browser to find a font that fits the category and is on your computer, or allow the user to specify preferred fonts:
try Cambria
I love using those in font settings:
- Standard font: Merriweather
- Serif font: Merriweather
- Sans-serif font: Rubik
- Fixed-width font: Space Mono
All these fonts can be found in Google Fonts.
Cambria is a decent modern serif font. It's legibile, which is great! But to my taste it doesn't have the elegance of a transitional font such as Baskerville.
Merriweather: I wouldn't mind it in light, rather than regular, which is a little heavy for my taste. I find the x-height digits a little weird. You can confuse digit zero with lower case o, rather than with capital O as in most fonts.
Rubik: Nope. The capital i is indistinguishable from the lower case L. That's the typical problem with sans-serif fonts, but there are exceptions: Inria, Raleway, Nunito, all near the top of Google's list, all have a little hook at the bottom of the lower case L. IBM Plex Sans also has crossbars at the ends of capital i, so you really never see a plain vertical bar and wonder what letter it is. Noto Sans is really good about distinguishing capital O from digit zero, another issue with sans serif fonts. But I think IBM Plex Sans is the winner here. (Oh I forgot to say, you also have to be able to distinguish vertical bar from those other things. And of course it's not good enough if you can tell which is which when you see them next to each other Il|1 (but that's a minimum requirement! which rules out whatever font I'm seeing here in the forum); you have to be able to see one of them in a gibberish machine-generated password dirncvlevuif and tell which character it is (such as the seventh character in that sample). IBM Plex Sans isn't even especially ugly, although once we're talking sans serif we've already abandoned hope of elegance.
Space Mono: It's okay. Most of the monospace fonts are ugly, of course. The least bad ones are the typewriter-like ones with super wide serifs, so that every glyph actually uses up the available space. The worst ones have no decoration at all, so the lower case i is just a vertical bar surrounded by an ocean of empty space. (Some such fonts do decorate the lower case L, so it does use up more of its space.) I think the dotted or slashed zeros in most monospace fonts are ugly, so I'm partial to FreeMono, which distinguishes letter O from digit zero just by width.
You may search for "web safe fonts"
.https://www.cssfontstack.com/
CSS Web Safe Fonts
Your Complete Guide to HTML Fonts (or Web Fonts)
I know that Atkinson Hyperlegible is designed specifically to be easy to read. I think it's on Google Fonts.
Interesting font. This font has some accessibility, for example, the zero has a slash in it, and the capital letter I has 2 horizontal lines in it.
But this font has some weird inconsistencies, for example, the 6 is curved but the 9 is straight:
There's also a font where 1 and I are indistinguishable, which is Koulen in Google Fonts.
The inconsistency is to make it easier to distinguish the two.
I like how this post's topic changed from a block that writes fonts to reviewing the fonts itself.
That happens often. I've seen one forum post turn into an English lesson, lol.
apparently there are such things as national fonts, like "TH Sarabun PSK"
Fonts are one of those things that people develop strong opinions about. My high school had a print shop, back in the days before computer printing, so we set type by manipulating pieces of metal, and did the actual printing on a semiautomatic press that applied an ink roller to the type and then pressed (hence the name) a piece of paper against the inked type, but the human operator had to get a piece of paper into position on the platform that did the pressing, right on time, without getting their hand pressed. It was fun. They taught us about typefaces. Back then it was a very esoteric interest; hardly anyone thought about typesetting. But now everyone has access to computer printing, and everyone's an expert. :~)
Automobiles are another topic that sucks people in. People argue about which cars are better than which. (In my youth that mainly meant GM vs. Ford, but now cars from many countries are available worldwide.) My kid (now an adult) used to be fanatical about the El Camino, which is sort of the Comic Sans of cars.
That's because those countries have languages with non-Latin alphabets, and most common fonts don't include their characters. Often they start with a common Latin-alphabet font and add their character set to it.
Hey @tethrarxitet, this library is really cute! Was is you who sent me pull-request for this? I closed one a while ago which seemed to have too much in it, but this one is just the right size, even though for my personal taste I'd probably strike the text costume and weight reporters, but I don't mind them too much, either.
If you're cool with this, I'll add this to the official libraries and credit you with it, okay?
Oh, wow, I feel so honored by your comment! Of course, you can add this to the Snap! official libraries. Feel free to alter any block definitions, comments, or help messages as needed. 
No, I did not send you a pull request for this. Whoever did, thank you.
I'm glad I will be forever a part of official Snap!.
And if I were to name this library, I would call this "Writing and Formatting"
My personal opinion on how the thing might look:
Writing and Formatting
A small but extensive library that expandsthe text-writing possibilities.
This adds formatting to the write block,
which makes it where you can bold and
italicize text, and there's an extra font
attribute to add spice to your text.
Thanks to Tethrarxitet for creating this
library.