DRY (Don’t Repeat Yourself) is a key principle in software engineering. It simply states that one should not reinvent the wheel while you are writing any application. If you have written some PHP application earlier, you will find that you are reinventing the wheel again and again to write the same process, like User Authentication, Database Management, Mailing Service, Validation System, etc. However, PHP now has effective and mature frameworks in hand that can perform nearly all the basic processes as stated above with their core. In fact, if you are smart enough, only then you will cherry pick the components from other frameworks like Zend, Laravel, Symfony, etc. This is the most hectic phase where you need to keep the dependencies of the required components, or else you will create a huge mess. Here are complete tutorial: http://www.cloudways.com/blog/composer-with-laravel/
require : {
"jelovac/bitly4Laravel": "3.*"
}