MathML
From Just Solve the File Format Problem
MathML is an XML-based format for displaying mathematical formulas, standardized by the W3C Math Working Group. It is supported by most modern browsers.
MathML is a low-level description not intended to be written by humans. MathJax (which also supports MathML polyfills for browsers that support it) is a popular way to generate MathML in web pages from LaTeX source.
