Comment 40 for bug 111061

Well, your point of windows lacking a theme engine in the old days is valid, but software that has been updated in the last 8 years or so usually supports theming, cause no windows developer would want their app to look bad on XP.
Sure, wine theming support is nowhere near complete, but that should be irrelevant, cause rendering through GTK should bypass that theme engine, as its not needed.
And yes, wine should work regardless of the user having GTK, Qt or whatever installed, but i don't see why this would be an issue. Wine can just try to open the GTK/Qt/etc library that it wants to use, and if it's not available, fall back to the old rendering engine. No one said the old way has to be deleted ;)