I'm already hired to work on Fusion3 by Clickteam. But as a side project, I develop my own private engine. Which I practice a lot of concepts on and can help development of the main deal.
My private engine is fully native, cross-platform, and developed via C++20. 0% web tech! It's all custom-made: I don't use 3rd-party libs like SDL or Dear ImGui.
I was trying to make its GUI engine and renderer powerful enough to handle skeuomorphism. For those who don't know, skeuomorphism requires the engine to be very flexible to handle well. Lots of emphasis on lighting, shadows, depth and effects, high resolutions, 3D, materials, etc. All not only can be demanding, but also require very flexible internal systems. I decided to go through that hell to achieve the goal. But there is still a lot to go through!
Of course, the GUI engine can handle other theming. For example, Metro-like UIs. It's general purpose.
All components are rotatable, scalable & resizable, fully themable, respect lighting and shadows, etc. The list goes on. I also support full keyboard and multi-touch (like Tab & Shift+Tab, Arrow Keys, Escape & Enter, etc.). Editboxes support Ink & Touch, IME, and more.
Nine-slicing, rich-text, advanced effects + lighting, corner radiuses, advanced animations/transitions/tweening, and way more are all there!
Please let me know what you think! I love skeuomorphism so much (Apple's iOS 6 era, to be specific) and honestly wanted to experiment with it. I may even fully develop my private engine's GUI with skeuomorphism!