As many know, you can download and install the “Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 file formats”, which allows you to use Office 2003 to read and write Open XML documents. The compatibility pack download is here.
here.There are some aspects of Open XML markup that are not supported by Office 2003, as Office 2003 doesn’t have the corresponding features. You can find details of what’s supported and what’s not
There’s also some great information on the compatibility pack on the Microsoft Office Word Team’s blog.
No news here – just posting here so that I’ll remember where all of this information is when I’m asked for it.