Overview of OpenMath and MathML

We give overviews of both OpenMath and MathML.
MathML allows both specification of semantics and presentation for a limited subset of mathematics. MathML is not extensible without some external definition resource.
OpenMath allows precise specification of semantics, it is not concerned with presentation, it is extensible (via. content dictionaries). OpenMath is seen as the premier contender as an extension definition mechanism for MathML.