@batfinkJun 08.2004 — #I do not think Opera supports it yet. I have read png format may be support opacity in Opera, but have not yet seen a working example. A server side code may be the workaround (but not real time).
@David_HarrisonJun 10.2004 — #I don't think that Opera ever will support filter. It's IE proprietary, -moz-opacity works for Moz and NN but that's also proprietary. Opera probably won't support transparency until it's used in the specs.
I've not read through the CSS 3 specs yet but I don't think there's any transparentcy styles in there.