Is there any software to get the kwin "show all windows" effect or transparent panels without having compositing?

(I am using xinerama for triple screening, thereby disabling compositing)

Thanks.

No. The "show all windows" effect, and similar effects cannot be done without compositing. Basically anything that requires real transparency or manipulating the appearance of windows requires compositing.

It is possible to make a hack so that the panel has the illusion of transparency under a limited number of situations by taking a snapshot of the underlying wallpaper and painting the panel on top of that, but it is pretty much a hack and won't work properly if you put a window behind the panel (in other words it will still show the wallpaper, not the window). This is not possible without modifying the panel software itself, though. It is impossible to get true transparency for the panel without compositing.