This is a simple horizontal group bar for the default UI. No custom graphics in this one, so it should work with any UI that's not too heavily graphical.
It's designed to work with the default UI on an 800 x 600 screen alng the top of the chat windows.
I use it with [ Alpha -> Normal: 50 ], and [ Alpha -> Faded: 0 ] so the group names and gauges just float above the chat.