One small note: the post seems slightly confused about the use of OpenType features, as it calls for:

    font-feature-settings: "colr", "calt";

I suppose this was intended to "activate" the color glyph table (COLR) in the font; but that isn't an OpenType layout feature that would be controlled by font-feature-settings, and doesn't need to be "turned on" like this.

(In addition, the 'calt' feature is (according to the spec[1]) supposed to be active by default, so it shouldn't be necessary to explicitly set it either. And indeed, the font works for me in both Firefox and Chrome without this rule; sadly Safari doesn't seem to handle it.)

[1] https://learn.microsoft.com/en-gb/typography/opentype/spec/f...

    sub Quote @Char' by @CharQuoted;
    sub Backslash.quoted Backslash' by Backslash.quoted2;
    sub Backslash.quoted Quote' by Quote.escaped;
    sub [@NonQuoteQuoted Quote.escaped Backslash.quoted2] @Char' by @CharQuoted;

    @Char = [a-z quotedbl backslash];
    @CharQuoted = [A-Z quotesingle slash];
    @NonQuoteQuoted = [A-Z slash];
    @Escaped = [asterisk dollar];
    
    feature liga {
      lookup xa {
        sub quotedbl @Char' by @CharQuoted;
        sub slash backslash' by dollar; 
        sub slash quotedbl' by asterisk;
        sub [@NonQuoteQuoted asterisk dollar] @Char' by @CharQuoted;
      } xa;
    } liga;
    feature liga {
      lookup xb {
        sub quotesingle' by quotedbl;
        sub slash' by backslash;
        sub dollar' by  backslash;
        sub asterisk' by quotedbl;
      } xb;
    } liga;

Putting animated SVG in a font [1] is a horrible hack; this one is benign.

A somehow larger stretch would be a font with a built-in spell checker, with a wavy underline under every letter that only disappears under correctly spelled words.

[1]: https://codepen.io/glukcodepen/pen/xQORev

Agreed, that is even more horrible. And probably just for performance reason alone should never ever get close to a real world product. Still, quite neat.

Impossible before. It can't be less invasive: _original text stays intact_ - no wrapping tags.. no JS.. just works with userContent.css.. - simply another dimension.

> I'm also not an OpenType expert, so I'm sure the substitution logics could be improved upon. I'm open to sharing the modified source file to anyone interested. If you have any ideas, suggestions or feedback, let me know. You can reach me at [email protected].

- so, how far can it be improved then ?!

- what other font editors moreover to Glyph (mac only) have good support for advanced contextual alternates ?

For font editors, Glyphs is the industry standard, and, as far as I know, there are not many good alternatives. There's FontForge, but its contextual alternate editing seems even more confusing: https://fontforge.org/docs/ui/dialogs/contextchain.html

Just today I found out about a new browser based font editor, fontra, but it looks like editing OpenType features is still on its roadmap. Maybe something to keep an eye on though. https://fontra.xyz/

Perhaps especially if the sibling comment about embedding a state machine pans out?

You asked what it takes to make a blog.

I have a html front page, tag pages and posts. All static.

There is a pretty short php page that takes an existing post or the dummy, chops off everything in front and behind the text.

The tag cloud sits under it. Clicking a tag injects it under the text.

When saved the top and bottom html are reatached and the title

is copied into the