MathML (or Mathematical Markup Language) is an application of XML customized for the transmission of documents pertaining to mathematics. The official Document Type Definition was created by the World Wide Web Consortium.

MathML is concerned as much with the meaning of mathematical formulas as it is with their presentation. This means, for example, that any instances of the tacit multiplication operator must be stated in the MathML source even though they are not meant to be shown on the display.

To give one example of the famous Euler identity in MathML:

There are programs available that convert TEX to MathML.