Mathematical Markup Language (MathML) is an application of XML for describing mathematical notations and capturing both its structure and content. It aims at integrating mathematical formulae into World Wide Web pages and other documents. It is a recommendation of the W3C math working group.
MathML is not intended to be written or edited directly by humans, but exceptions are more likely to be made for Presentation MathML than for Content MathML.
Read more about MathML: History, Presentation and Semantics, Example and Comparison To Other Formats, Embedding MathML in XHTML Files, Embedding MathML in HTML5 Files, MathML Version 3, Other Standards