Does GTK+ on Windows and OS X use the native widgets or are they emulated?

Question

Do GTK apps look native in those environments?

Answer 1

No, GTK does not look native on either Windows/Mac. There are themes to improve the visual differences, and there are also some projects working on making GTK look and behave more natively, such as IGE-mac, GTK Quartz.

All in all, GTK on Windows is closer to native than GTK on Mac, so it should be possible to get a native looking GTK on Windows with a little effort. If you really need a toolkit that looks native on Windows/OSX/X11, and you're not limited to C, I think QT is a little closer to accomplishing that than GTK is at the moment.

Answer 2

Neither GTK (nor Qt) looks particularly native on Windows, particularly if the native theme is one of the modern ones. The challenge is due to the way that the newer GUIs are drawn.

But that's as nothing to how out-of-place they both look on OSX. There, the main problem is that the platform standards for laying out and interacting with GUIs are totally different. You can't easily hide the difference between a modal and a non-modal dialog! And where the buttons are placed (and exactly which buttons are placed) and how they all behave, that's all different too.