As a very much work-in-progress, yesterday, I started working on interactive equations https://p.migdal.pl/equations-explained-colorfully/ (it uses KaTeX under the hood).
The idea is similar to https://betterexplained.com/articles/colorized-math-equation..., but with mouseover interaction (both for further description, but also for accessibility). For a deeper dive in the topic of explorable explanations, I wrote https://p.migdal.pl/blog/2024/05/science-games-explorable-ex... (was here on the HN as well).
This is really awesome! I've been really interested in creating an interactive introduction to basic algebra where parts of the equation can be manipulated using drag-and-drop, but I couldn't really figure out the best way to do it. Maybe using Katex is the way to go?