Wireshark — an awesome network protocol analyzer & one of my favorite tools — recently announced that they're switching their GUI from GTK+ to Qt. This makes the app fit in better with the operating system's native UI elements and opens up opportunities for additional platform support (i.e. tablets).
The switch is especially relevant to Mac users because the app no longer requires X11. I downloaded the development release and confirmed that it is light years better than the old version.
This is a pretty big deal. (see what I did there?)