OpenXML

This technology from microsoft

OpenXML SDK 2.0

This is for Office 2010 and .NET 3.5

• http://www.microsoft.com/en-us/download/details.aspx?displaylang=en&id=5124

Here an article on how to use it:

"How to create a document from a template (dotx, dotm) and attach to it using Open XML SDK":

• http://blogs.msdn.com/b/vsod/archive/2012/02/18/how-to-create-a-document-from-a-template-dotx-dotm-and-attach-to-it-using-open-xml-sdk.aspx