The other day, I was looking into how easy it is to render LaTeX via a Markdown document. MathML isn’t yet widespread enough to use reliably, so instead I started looking at some of the third-party libraries available. I had looked at KaTeX from Khan Academy a few times in the past, and was happy to find that it was exactly what I wanted.
To add support, all you need is KaTeX, auto render support, and the CSS file:
<script src="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.6.0/katex.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.6.0/contrib/auto-render.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.6.0/katex.min.css">
Then, in Markdown, you can write your LaTeX within $$ blocks.
$$
a = \\sqrt{b^2 + c^3}
$$
This renders like so:
$$ a = \sqrt{b^2 + c^3} $$
The auto render plugin can be configured to ignore certain tags or check for custom delimiters; there’s more about that in the GitHub repo. KaTeX can also take a LaTeX string and spit out formatted HTML, which is probably the better option if you’re happy to do a little more work for raw performance, but as it is, this works great.
Another option for this is using Kramdown’s LaTeX support with MathJax, but I had some issues getting it to render correctly in some cases (and it seems a bit slower than Khan Academy’s alternative).