While the Australian government is a Microsoft only shop, it appears that it wants the open document standard adopted. The office of the Australian Government Chief Technology Officer (AGCTO) is proposing support for the Open Document Format (ODF) in an annual review of computing system policies.
AGCTO John Sheridan wrote in his bog that the new draft now requires that office productivity suites must provide support for at least version 1.1 of the Open Document Format for Office Applications (ODF). ODF is the standard Extended Mark-up Language (XML) document format used by governments in many countries, including Japan, India, the European Union, Brazil and South Korea as well as the North Atlantic Treaty Organisation defence pact.
ODF is is supported by Microsoft with its Office suites since version 2007 Service Pack 2, and Lotus Symphony, Oracle Staroffice and Google Docs. But Redmond would prefer people used its own docx standard. The reason is that open source software such as AbiWord, OpenOffice, and LibreOffice supports the format and if you use the standard you might as well use them.
Ironically the interoperability and support for several versions of Microsoft Office is cited by the AGCTO as reasons to go with ODF, along with flexibility and the fact that the format is continously updated and developed. Microsoft's Office is still the preferred productivity suite according to the SOE build draft document.