Wolfram Research, Inc.
1.11.7 Exchanging Material with the Web
Converting notebooks to HTML.
HTMLSave has many options that allow you to specify how notebooks should be converted for web browsers with different capabilities. You can find details in the Additional Information section of the online Reference Guide entry for HTMLSave.
Converting to and from MathML.
Here is an expression printed in MathML form.
If you paste MathML into a Mathematica notebook, Mathematica will automatically try to convert it to Mathematica input. You can copy an expression from a notebook as MathML using the Copy As menu in the notebook front end.