The Office Open XML format may not yet have been ratified by the ISO but Microsoft is already preparing to release a software development kit.

Microsoft plans to put out the final beta of the OOXML SDK next month, and put out version 1.0 in May, according to Doug Mahugh, a technical evangelist with Microsoft.

The SDK will enable developers to write applications that can open, read, and/or otherwise work with OOXML documents, or port existing applications that work with documents in older Microsoft formats over to OOXML, Mahugh said. Moreover, the SDK will "put Microsoft on the hook to keep your app in line with the OOXML standard" as it changes, he said.

For instance, if national members of ISO decide at the end of this month to approve the OOXML specification - which has been changed substantially since its failure to pass last September - those changes will be reflected in Version 1.0 of the SDK, Mahugh said. And Microsoft would continue to update the SDK to make sure that applications built with it remained compliant with an Open XML standard as changes were made in the future, he said.

Microsoft first released a Community Technical Preview of the SDK last June. It is targeted at developers of business intelligence, content management and other applications in the Office and SharePoint ecosystem. Thealso offers an API for packaging OOXML for developers who need "more low-level control" over their code, Mahugh said.

Microsoft plans to release a CTP of an improved version 2.0 of the SDK in July, with a final release "coming out during the Office 14 wave," the timing of which hasn't been announced yet, Mahugh said.

The V1 technical committee advising the US representative to ISO voted last week in favor of OOXML's approval. That representative, a group called INCITS, had already voted for OOXML's approval last September.

INCITS will hold a vote on Friday to re-affirm the U.S.' position, which requires an unanimous result as detailed in the relevant INCITS documentation. If that fails, INCITS' Executive Committee will start a process of proposing and voting on resolutions in favour or against OOXML, a process which could take many days.