I have several documents in word 2016 with a few hundred equations written in the native word equation format (i think it is omml). I want to convert every equation to mathml. what is the quickest way? I have already installed mathtype but it says omml2mml.xsl missing. Even after locating the file and putting it where the mathtype website said, it is showing same error. How to fix it?


There exists an open source framework called transpect.
It's purpose is conversion of complete documents from and to individual formats. (docx, TeX, html...)
Among others, docx files are supported as input:


If you have git or svn installed, you can simply follow this guide for a basic setup:


The guide describes converting the whole docx document into hub.xml (basically docbook+css).
Both, MathType and OMML equations are translated to MathML during conversion.
You can simply extract the mml:math elements from the hub.xml, using any tool you like.

There exist more transpect modules, to convert the hub.xml to your desired format completely.
That requires more time for setup, so it depends on what you intend to do with the results.


The old Word Equation Editor was built upon MathType.
The new Word Equation Editor is based on OMML.

A MathType-Equation is displayed as an image in Word.
If you have MathType installed, a separate window opens if you click to edit the equation.
Else, you cannot edit it.
New equations (OMML) can be edited directly inside the Word software.

OMML and MathML are both XML-formats.
omml2mml.xsl is a file provided by Microsoft to go from OMML to MathML.
transpect uses a modified variant of it, because the original file has several flaws.
(There also exists mml2omml.xsl, to go from MathML to OMML)

MathType uses a non-XML-structure for its equations.
MathType can import MathML equations, but not OMML.
MathType therefore requires the omml2mml.xsl file to generate MathML first.

On a side note, MathType does not always preserve character styles (bold/italic) when exporting to MathML/TeX.

To support all equation-types in Word, and to improve the performance of conversion, transpect is able to translate MathType to MathML.

For your info: I am a contributor to the transpect project.

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