OpenOffice.org 3 can open Word 2007 files in the .docx format, but it cannot save in that format. So, assuming you want to edit files you take home from school, you could save them in Word 97-2003 format, that is, the .doc format, at school before you take them home. That way, you can edit them at home with OpenOffice and save them to the older Word format which can then be opened at school with Word 2007.