MathJax is a cross-browser JavaScript library that displays mathematical notation in web browsers, using MathML, LaTeX, and ASCIIMathML markup.

[8] MathJax is used by web sites including arXiv,[9] Elsevier's ScienceDirect,[10] MathSciNet,[11] n-category cafe, MathOverflow, Wikipedia (on the backend),[12][13] Scholarpedia, Project Euclid journals,[14] IEEEXplore,[15] Publons, Coursera, and the All-Russian Mathematical Portal.

[17] MathJax can display math by using a combination of HTML and CSS or by using the browser's native MathML support, when available.

[17] MathJax also supports math accessibility by exposing MathML through its API to assistive technology software, as well as the basic WAI-ARIA "role" and older alt attributes.

[20] The MathJax architecture is designed to support the addition of input languages and display methods in the future via dynamically loaded modules.

MathJax also includes a JavaScript API for enumerating and interacting with math instances in a page.

Any MathJax equation displayed in a supported browser can be copied out in MathML or LaTeX format via "Show Math as" sub-menu if right-button clicked or control-clicked on it.

Then it can be pasted in any equation editor that supports MathML or LaTeX, such as Mathematica, MathType, MathMagic, or Firemath, for re-use.