" I can send a document in any of those formats to almost anyone in the world and expect it to be opened."

Assuming they've spent $100, $200, $400 on the right Microsoft Office software. And as was pointed out, Microsoft Office has not been very compatible with Microsoft Office.

I'll one up the poster above you - through Office XP, Word saved margin information based solely as an offset from the margins of whatever the default printer was in Windows. This meant that if you opened the document on another machine - even with the same version of Word! - the margins/formatting could be different if the default printer on different on that machine. Heck, if you changed the default printer on the machine the document was created on, your files would then appear different!

Open Office dealt with this by surveying many machines for their default printer settings and then creating an average and using those average margins to open Word documents. The result? Often, Open Office was MORE ACCURATE to the original document than opening it with Word itself!

And again, you still don't quite grasp "standard". I can send a document in PDF format to absolutely anyone in the world and expect it to be opened CORRECTLY, regardless of operating system or version or what PDF reader's used. That's because PDF is now an ISO standard format and any developer can implement it in their products.

What version of PC users can open an .odt file? 100% of course, especially since they can download LibreOffice or OpenOffice among others for free. Since it's a sane standard rather than a dictated defacto standard, it's designed well enough that you don't have to worry about version incompatibilities or printer margins like you do with Word.