You may remember that LibreOffice 3.5 learned to import RTF OLE objects (including math expressions) in Writer. In LibreOffice 3.7, the same is now true for math expressions expressed using native RTF math markup:
If you are interested in the details, then the nice thing about this implementation is that:
The importer internally turns RTF markup to OOXML tokens, and that does the hard job.
The non-XML-specific part of the existing OOXML export was abstracted to a base class, and that’s the driver of the RTF exporter.
So if you like this new feature, don’t forget to thank Luboš Luňák, who is the author of the OOXML math import/export. :-) In case you way to play with this feature, test documents are available.