Unix executable file

I recently obtained a G5 (powermac 7.2 running 10.5.8) after being exiled on a pc for two years. I opened a CD containing files I saved from my previous Mac (a G4 running 10.3.9) on the G5. Most of the files opened with no problem. However, nearly all of the articles I wrote (using Appleworks, saved as RTF documents) showed up on the G5 as a "Unix executable file." I don't even know what that is, except for the reference to Unix.
I know very little about Unix. Is there anything I can do to salvage these documents?
As a secondary question, will the hard drive from the G4 work if I install it in the G5?
Thank you for your help.

OS X represents any file as executable if it has that permission set on it (I won't go into detail here but suffice it to say, this isn't a huge problem). If you know that the files are RTF files and they don't have an extension signifying this, add one. Otherwise, you might be able to open these up in your editor of choice regardless.