OpenMath

An XML-based standard for representing mathematical objects and their semantics in a machine-readable format. Unlike MathML, which has both presentation (visual layout) and content (semantic structure) modes, OpenMath focuses purely on semantic meaning, defining mathematical symbols through Content Dictionaries that provide formal definitions, descriptions, and examples. This semantic richness makes OpenMath particularly useful as an interchange format for converting between different mathematical notations and for providing meaningful aural descriptions of mathematical expressions in accessibility applications.