The first version of the software developer kit (SDK) for Open XML has been released to the web. The Open XML document standard is awaiting publication by the International Organization for Standardization (ISO). The SDK is designed to help you produce code in your applications to create, access, and manipulate Open XML documents.
The SDK includes an application programming interface (API) for simplifying the creation of code for searching documents, creating documents, validating document parts, modifying data and other tasks.
You can get the version 1.0 SDK from Open XML Format SDK. A pre-release of version 2.0 of the SDK is planned for late this summer that will support the details of the ISO standard that was approved in March.
The standards are available on the ISO site as IS29500.