The latest versions of office support open XML formats(docx,xslx etc) which are XML files basically. It's not mentioned in the article but using open XML SDK is

The latest versions of office support open XML formats(docx,xslx etc) which are XML files basically. It's not mentioned in the article but using open XML SDK is the supported way for working with office docs https://msdn.microsoft.com/en-us/library/office/bb448854.aspx https://msdn.microsoft.com/en-us/library/office/bb448854.asp...