I've been using OpenOffice for many years. Planning to start using Smashwords, and the the Style Guide is rather opaque on the subject of alternatives to Word. I'm pretty sure I can do most of the formatting stuff that is required (maybe all of it) in OO -- but OO allows files to be saved in three different .doc file formats: Word 95, 97/2000, or 6.0.
Which should I use? And will it work? Have others been successful using OO and exporting .doc files? This is for novels, nothing with graphics.
I use LibreOffice which is similar to OpenOffice. You can output to 97/2000 which is the .doc format I've used for Smashwords.
Once your OO file is complete then use Calibre to convert the file to ePub. Check the ePub file using the Validation tool and if there are no errors you know the Smashwords converstion will go through okay.