// to be later registered at runtime extern var ObjC; // list here all the ObjC classes to register and use var Alert func loadObjCClasses() { Alert = ObjC.register("NSAlert") } func main() { loadObjCClasses(); // ObjC Hello World var alert = Alert() alert.messageText = "Hello World" alert.informativeText = "Hello from Gravity!" alert.runModal() return 0 }