Composer چیست؟

{
        "name": "zendframework/skeleton-application",
        "description": "Skeleton Application for ZF2",
        "license": "BSD-3-Clause",
        "keywords": [
                "framework",
                "zf2"
        ],
        "homepage": "http://framework.zend.com/",
        "require": {
                "php": ">=5.3.3",
                "zendframework/zendframework": "~2.3"
        }
}

$ php -r "readfile('https://getcomposer.org/installer');" | php

$ composer install

$ composer update

$ composer show

$composer require phpmailer/phpmailer