I'm not a windows fan or windows user but imagine if an user ran your java app in windows , your app could use special windows features like taskbar progress !
Now it's possible (on other OS's your app will run normally without these features). JTaskbarLib is my first java open source library. it can also change the window opacity in a decorated JFrame !

This is my project in github:
https://github.com/alireza6677/...