So I get excited when GUI toolkit projects get posted on HN. And then I'm usually deflated when I look at the screenshots. I know they haven't built these programs themselves, so it's not necessarily their fault that these developers have gone with the everything-and-the-kitchen-sink style of UI design. But they also chose to feature these particular projects, so someone there thinks these are good examples, which does not speak well towards their commitment to enabling good design. https://www.wxwidgets.org/about/screenshots/
Most of these examples feature something you should never do: selectively replacing the standard widgets from your operating system's toolkit. Either create/use a different toolkit entirely or use the defaults, don't mix and match.
It's disheartening to think that, in 2016, the least-bad way to design a UI is to wrap up a browser as a widget and sling HTML/CSS.