In the age of multiple available operating system a programmer often faces a problem of choosing the platform for his project. This choice is often not trivial. Sometimes certain functionality is available only on selected platforms, sometimes user tastes change and they migrate from one platform to another (for example Symbian was dropped because of huge interest in Android), many application are written for multiple platforms from the beginning. It is often best to write code that is platform independent and if that is not possible – to somehow manage existence of multiple platforms in the most simple way.