Here at the Open XML workshop in Paris this week, Jerome Berthaud pointed out to me that my CreateXlsx sample program required a bit more than just updating to the final Ecma schemas in order to get it running under the RTM. It seems that there are some elements in the style part that are required, which you could get away with omitting in the past.
So I've updated CreateXlsx and CreateDocx with all the necessary changes to make them work with the final Ecma schemas and RTM version of Office 2007. The source code is attached.
These two sample programs create the minimal DOCX and XLSX from scratch, so you can use them as starting points for developing solutions that create these types of Open XML documents. For more information on how they work, see these blog posts:
If you're wondering "what about that CreatePptx version you've said is coming soon?" ... that's coming soon. :-) Creating the minimal "hello world" PPTX is more complicated than creating the minimal DOCX or XLSX, so I'm going to use it to demonstrate a simpler approach for generating complex Open XML documents from scratch.