OK. There is this #TeXLaTeX Package tcolorbox.
It makes colorful boxes around text.
Its manual is 550+ pages.
I think it is a main driver of @typst@mastodon.social adoption.
So @tobsboe@machteburch.social recently had to update it and now the newest texlive in Fedora is too old to use the package because it needs newer ‘kernel features’.
And now we wonder: Do they mean TeXLive or Linux?