well,while concerning operating systems,java is too much backdated.but java scripts are really useful for security engineers while finding any vulnarabilities and also for programmars.and android is the best mobile phone OS ever invented,i think.
Dare: text someone this -"I Like It When You Sleep, for You Are So Beautiful Yet So Unaware of It" and then take a screenshot of his/her reply and post it here :3 (skip it if you want)