got one copy of Office 2008 here, and it's the only app that's able to open docx files.
does it quite well
it's got other features and the toolbars are re-arranged.
A lot of Mac programs will open the docx files, Pages & Text Edit being a couple.
Office 2008 doesn't have VB (Visual Basic) support and that breaks quite a bit (like the above mentioned macros). MS has had lots of complaints about removing this feature and it will return in the next version of Office.
You really should have an Intel Mac to run Office 2008, it's a bloated piece of software at best. It'll run dog-slow on a PPC.