O site do LibreOffice diz:
To guarantee that your documents can be opened by the widest range of products and far into the future, save your documents in OpenDocument format, the new international standard for text documents. This XML-based format means that people opening your files are not obliged to use Writer: they can be accessed using any OpenDocument-compliant software.
Writer easily reads Microsoft Word documents, and you can also save your work in Microsoft Word format, for sending to people still locked into Microsoft products. LibreOffice can also open .docx files created with Microsoft Office 2007 for Windows or Microsoft Office 2008 for Mac OS X.
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