hbox

Two commands I used all throughout my thesis are: \def \rV#1{\hbox{$#1$\kern-0.38em\lower0.85em\hbox{$\vec{}\,$}}\,} and \def \Vec#1{\hbox{$#1$\kern-1.0em\lower0.4em\hbox{${\scriptstyle \rightarrow }$}}} These won't work in MathJax (understandably).

The problem is that, maddeningly, they chose to have non-math commands like kern and lower work exclusively in math mode, and not outside one like in a hbox.

Therefore, if you change your second command to something like this: $a \kern-1em\lower0.4em\hbox{$\scriptstyle \rightarrow$}$ then it will work in MathJax.

I get that this is preprint, but the reference on page 8 has an overfull hbox with a rather high badness.

Just Vbox container Hbox container text container etc.

I really miss the HBox and VBox of Adobe Flex.

Last time I checked, the vbox/hbox is XUL.

V-scrolls in single line inputs, my hbox/vboxes start fighting over margins when nested, labels don’t baseline align with input texts and look real ugly, scrollbars suddenly pop up into existence because something is 1px larger than expected.

Most engine primitives (\hbox, \def, \relax, etc.) and Plain TeX macros (\quad, obreak, \bigskip) work in both LaTeX and ConTeXt, and the math syntax is almost identical between LaTeX and ConTeXt too.

All of its vbox/hbox code is already obsolete as of flexbox but it doesn't use flexboxes (instead it manually calculates everything, and it's about 1000x slower than the browser at this, and I can provide benchmarks of this if you'd like).

Something with consistency (is it \$CMD{...}, \begin{$CMD}...\end{$CMD} or \{$CMD...}?), better error messages, more specific and targeted warnings (most hbox-full warnings can be ignored, but many can't!), support for specifying `-Werror` (like gcc) and other things like that.

If you could mention what these programs are that are somehow completing the rest of their GTK4 ports in a small amount of time, refactoring everything to use the new improved widgets and rendering system at incredible speed, but are taking hundreds of thousands of man hours to replace the word HBox with Box, maybe someone can look at them and advise them on how to do that faster.

And the concerns you have about people not knowing what an "underfilled hbox" means is simply a lack of training.

Also, it's borderline unusable to anyone who hasn't mastered what "underfilled hbox" means and the like.

When TeX can't format a paragraph beautifully, it emits diagnostics like "overfull \hbox".

It is possible (though very rare) to get a situation in LaTeX where it keeps oscillating between two possible “solutions” - usually forcing a hbox width will stabilize it.