unoconv converts between any document format that OpenOffice understands.
It uses OpenOffice's UNO bindings for non-interactive conversion of
documents.

Supported document formats include: Open Document Text (.odt),
Open Document Draw (.odd), Open Document Presentation (.odp),
Open Document calc (.odc), MS Word (.doc), MS PowerPoint (.pps/.ppt),
MS Excel (.xls), MS Office Open/OOXML (.xml),
Portable Document Format (.pdf), DocBook (.xml), LaTeX (.ltx),
HTML, XHTML, RTF, Docbook (.xml), GIF, PNG, JPG, SVG, BMP, EPS
and many more...