Those cases are inherently platform specific and are impossible to abstract completely. UI for example. Pure Java UIs plain suck; you can use Gtk# in C# for th

Those cases are inherently platform specific and are impossible to abstract completely. UI for example. Pure Java UIs plain suck; you can use Gtk# in C# for the same thing, but none will be up to the platform's UI standards. Besides, the JVM isn't available on iOS and Android, so it isn't universally available either.