This is an object-oriented library, the main priority of which is the maximum possible performance. It works on the double buffering concept, it has a lot of widgets, animations and custom event handlers support. All programs from the screenshots above are implemented with its help. If you want to develop a fast and beautiful program in just a few lines of code without butthurt - then this library is made for you.
Detailed illustrated documentation, installation methods and tons of practical examples are available at:
https://github.com/IgorTimofeev/GUI