The open source community has produced an alternative format, the OpenDocument format. It's an ISO standard, and anyone can use it freely.
Normally I use OpenOffice.org Writer to edit documents. But I decided to try KWord from KOffice, since it is much faster, and... why not? I like to use new stuff. :)
But KWord can't export to PDF (it can use KDE's "print to PDF" option, but my printing is kind of broken when I'm not at home). So I saved in OpenDocument format, and imported into Writer. No love - the formatting is totally broken! I tried to load into AbiWord, but it doesn't understand OpenDocument format at all.
In the end, I saved it as Microsoft Word document - which all 3 programs load and save more-or-less accurately.