If you are using FrameMaker 8, you can use "Track Text Edits" for review purposes. This of course assumes that reviewer also has a copy of FrameMaker 8 and you can trust the reviewer with the source files.
For review of the final output, PDF based commenting is probably the best bet. You may also want to check the "Merge Comments" functionality in Acrobat when you send the PDF out to multiple reviewers. Thanks and regards Vivek Jain
