Concerns when Switching Offices to Linux and StarOffice?

Reezle asks: "I am a reluctant Microsoft Engineer who has a few customers sitting on the fence whether to go the XP route, or bite the bullet and switch an entire office over to Linux. I would love to assist them, and educate myself at the same time, but am unsure of the limitations of file type interoperability between MS Office, and Linux programs (Star Office is the only one I'm familiar with). I assume anything they create could be saved in formats that their business partners will be able to open (i.e. RTF), but what happens when they receive attachments encoded with Office 2000 or XP (ie DOC, XLS, PUB, etc)? I'd love to encourage them to make the switch, but would hate to see them unexpectedly cut off from the people they need to communicate with. Any help/advice would be appreciated."