At Spectre600's suggestion, I have installed the latest version of Ubuntu Mate on the dual Xeon system I had originally run Windows Vista Ultimate on (Vista is no longer receiving Microsoft support while this Linux LTS release will be supported for years).
Surprisingly, this is a really nice distro.
Stable, easier to use than Linux distros I have tried in the past, with a fantastic level of customizability.

It should be a nice alternative for the X5000 and our G5's (to MorphOS and OS4 when mainstream software is required).
Actually, it appears to be our BEST alternative (for an mainstream OS).

So..I'd like to post thanks to Spectre660 for his help.

Jim


[ Edited by Jim 04.05.2016 - 21:00 ]