Thanks! I got what I asked for, but perhaps my question wasn't right. The file I found is
Retrospect Client for Red Hat Linux 6.5.108 (.rpm)
But it seems to indicate that it's for Retrospect Mac 5.1/Win 6.5.
I am running Mac OS 10.4.1 (Tiger) and Retrospect 6.0.212.
The Red Hat Enterprise Professional WS is "version 3" which, if I understand it correctly, is the Anaconda (9.1) release. (I'm not sure about the latter. It definately is "version 3" and it is the most up-to-date version according to the Red Hat up2date utility.)
Will Retrospect Client for Red Hat Linux 6.5.108 work with Retrospect 6.0.212 running on a Mac? If the answer is either "don't know" or "not officially supported" I am quite willing to give it a go. But if the answer is "absolutely not -- we tried and it failed" then there's no use me trying.
Does anyoue have any experience with this? (If I do try it, I will post the results for the benefit of all.)
By the way, Retrospect running on the Mac has served me so well for so long that I have no desire to switch to Windows ... even if it means leaving the LInux box without a backup!