[phkahler]

I'm used to agree. That's how you get a native look and feel, but I don't think that's necessarily what people want. I find the use of tabs in the browser to be very telling - it means the way OSes have handled multiple instances of an application are not satisfactory, so people want the browser to handle that. Once it's in the browser people will want it to be the same on all platforms.

[blt]

Someone should survey software end users to figure out if they care about native-looking UIs. I have a feeling most users don't care very much.

My most-used GUI apps are Chrome, Visual Studio, Ableton Live, and Photoshop. All of them have heavily customized user interfaces. Their custom controls and tiling/layout systems are tailored to the application domain. Except for Chrome, these are "do your life's work" applications. They should aim for maximum productivity, even if it makes the application harder to use. I think they would suffer if they tried to "look native".

Most everything else is done in web apps these days. Users don't seem to have a problem dealing with different button CSS in different web apps.

Certain things, like the "open file" dialog, really suffer if they look non-native. But I think users don't care about most other cases.

[pcwalton]

In a sense, Chrome has been moving further and further away from being native over time; in-content preferences, for example.

[kaolinite]

There's nothing wrong with designing custom UI elements, so long as they're done properly on each platform. For example, Safari's tabs are completely custom (as far as I know) - they can't be used in other applications, they aren't part of Cocoa - but they're tastefully designed and they work well.