Composer is a Dependency Manager for PHP. This vim plugin is a wrapper for php composer.phar command. You can call :Composer about for example.

:ComposerInstall is a shortcut for php composer.phar install.

:ComposerUpdate to run php composer.phar update.

:ComposerOpenJson to open composer.json file in a new buffer.

:ComposerOpenLock to open lock file.