[simoneau]

jsMath, now MathJax, took all the wind out of MathML’s sails by rendering LaTeX equations in the client. I know that MathML is better in some ways, but the combination of downloading custom fonts and JavaScript-based layout solved the problem well enough.

[WorldMaker]

My understanding was that the early versions of jsMath/MathJax started by converting LaTeX to MathML in the brief few years of relatively common browser MathML support and still uses something very like MathML for internal representations and still supports MathML as the output format.